JP6728653B2 - Non-aqueous secondary battery and manufacturing method thereof - Google Patents

Description

The present invention relates to a non-aqueous secondary battery and a method for manufacturing a non-aqueous secondary battery.

A non-aqueous secondary battery such as a lithium-ion secondary battery (hereinafter sometimes simply referred to as “secondary battery”) has characteristics that it is small and lightweight, has high energy density, and can be repeatedly charged and discharged. Yes, it is used for a wide range of purposes. A secondary battery generally includes a positive electrode, a negative electrode, and a battery member such as a separator that separates the positive electrode and the negative electrode to prevent a short circuit between the positive electrode and the negative electrode. It is manufactured by injecting an electrolytic solution into a solid.

Here, in recent years, in secondary batteries, a battery member including an adhesive layer for the purpose of improving the adhesiveness between the battery members, and a porous film layer for the purpose of improving heat resistance and strength is used. ing.
Specifically, an electrode formed by further forming an adhesive layer and/or a porous membrane layer on an electrode base material formed by providing an electrode mixture layer on a current collector, and an adhesive layer and/or a separator base material. Alternatively, a separator formed by forming a porous membrane layer is used as a battery member. And the adhesive layer and the porous membrane layer are usually a slurry for an adhesive layer or a porous membrane layer, which contains a component for exhibiting a desired function, a binder component, and a dispersion medium such as water. The composition is formed by supplying the composition onto a suitable substrate such as an electrode substrate or a separator substrate and drying the composition.

Therefore, in recent years, attempts have been made to improve the adhesive layer and the porous membrane layer provided on the base material in order to further improve the performance of the secondary battery.

For example, in Patent Document 1, a particulate polymer having a core-shell structure including a core part and a shell part that partially covers the outer surface of the core part, and a binder containing an acrylic polymer are described in Lithium Ion A technique used for forming an adhesive layer for a secondary battery is disclosed. Further, Patent Document 1 discloses a technique in which alumina and a binder containing an acrylic polymer are used for forming a porous membrane for a lithium ion secondary battery. Then, in the technique described in Patent Document 1, by providing the above-mentioned porous film on the separator base material, and further providing the above-mentioned adhesive layer on the porous film layer, the adhesiveness between the electrode and the separator in the electrolytic solution is improved. The production of a lithium-ion secondary battery that is superior in low temperature output characteristics and high temperature cycle characteristics is realized.

International Publication No. 2015/064411

Here, in order to achieve further performance improvement of the secondary battery, in addition to high adhesion between the electrode and the separator and good output characteristics, for example, the swelling of the battery is suppressed even when the battery is repeatedly used, It is required to realize good battery performance such as deterioration of the battery. However, the lithium-ion secondary battery described in Patent Document 1 has room for further improvement in adhesion between battery members, output characteristics, and a good battery state after repeated charging and discharging (cycle). ..

Therefore, the present invention provides a non-aqueous secondary battery capable of arranging excellent battery performance such as high adhesion between battery members such as electrodes and separators, good output characteristics, and good battery condition after repeated cycles. The purpose is to do.
Further, the present invention is a non-aqueous secondary battery capable of producing a non-aqueous secondary battery having high adhesion between battery members, excellent output characteristics, and excellent battery performance such as a good battery state after repeated cycles. It is an object to provide a method for manufacturing a battery.

The present inventor has made earnest studies for the purpose of solving the above problems. The present inventor, in a secondary battery including an adhesive layer containing a predetermined component and a surface of a porous film layer or an electrode in contact with the adhesive layer, the particle diameter of the organic particles contained in the adhesive layer, and the adhesive layer Attention was paid to the control of the surface roughness of the surface of the porous membrane layer or the electrode in contact with. Specifically, the present inventors have found that when the particle diameter of the organic particles contained in the adhesive layer and the surface roughness of the surface of the porous membrane layer or the electrode in contact with the adhesive layer satisfy a predetermined range, the secondary battery It has been found that the adhesion between the electrode (positive electrode, negative electrode) and the battery member such as the separator can be improved. As a result, it was confirmed that the secondary battery manufactured by using the adhesive layer and the porous film layer in contact with the adhesive layer can have good battery performance such as output characteristics and battery state after repeated cycles. Was completed.

That is, the present invention is intended to advantageously solve the above problems, the non-aqueous secondary battery of the first aspect of the present invention comprises a positive electrode, a negative electrode, a separator, and an electrolytic solution, 4. The separator has an adhesive layer containing organic particles, at least one of the positive electrode and the negative electrode has a porous membrane layer in contact with the adhesive layer, and the surface roughness Ra of the porous membrane layer is 0.1 μm or more. It is 0 μm or less, and the volume average particle diameter Dp of the organic particles is 0.2 μm or more and 5.0 μm or less (hereinafter, “non-aqueous secondary battery (I)” or simply “secondary battery ( I)".).

Further, the non-aqueous secondary battery of the second aspect of the present invention comprises a positive electrode, a negative electrode, a separator, and an electrolytic solution, the separator has an adhesive layer containing organic particles, at least the positive electrode and the negative electrode. On the other hand, the surface roughness Ra of the surface in contact with the adhesive layer is 0.1 μm or more and 5.0 μm or less, and the volume average particle diameter Dp of the organic particles is 0.2 μm or more and 5.0 μm or less. (Hereinafter, may be referred to as “non-aqueous secondary battery (II)” or simply “secondary battery (II)”).

Like the secondary battery (I) and the secondary battery (II), the volume average particle diameter Dp of the organic particles contained in the adhesive layer and the surface roughness Ra of the surface of the porous membrane layer or the electrode in contact with the adhesive layer are If the predetermined range is satisfied, the adhesiveness between the electrode and the separator can be improved in the secondary battery having the adhesive layer and the porous membrane layer. Further, the output characteristics of the manufactured secondary battery and the battery performance such as the battery state after repeated cycles can be made excellent.
In addition, in this invention, "surface roughness Ra" points out the arithmetic mean roughness based on JISB0601:1994. In addition, in the present invention, the “surface roughness Ra” can be measured using a nanoscale hybrid microscope (manufactured by KEYENCE CORPORATION, product name “VN-8010”).
Further, in the present invention, the “volume average particle diameter Dp” means a particle diameter at which the cumulative volume calculated from the smaller diameter side in the particle size distribution (volume basis) measured by the laser diffraction method is 50%.

Here, in the secondary battery (I), the porous membrane layer preferably contains non-conductive particles. In this way, the porous film layer having a predetermined component and a predetermined surface roughness is brought into contact with the adhesive layer having a predetermined component and a predetermined particle size, thereby improving the adhesiveness between the battery members. Because you can. Moreover, it is because the secondary battery manufactured by using the porous membrane layer can have more excellent battery performance such as output characteristics and battery state after repeated cycles.

The organic particles preferably have a glass transition temperature of 10°C or higher and 110°C or lower. In this way, when the adhesive layer includes the organic particles having the glass transition temperature in the above range, in the secondary battery having the adhesive layer, the adhesiveness between the electrode and the separator can be improved. is there. Moreover, it is because the secondary battery manufactured by using the organic particles can have more excellent battery performance such as output characteristics and battery state after repeated cycles.
In the present invention, the “glass transition temperature” can be obtained from a differential scanning calorimetry (DSC) curve obtained by using a differential thermal analysis measuring device (reference substance: aluminum), and specifically, the present specification It can be measured using the measuring method described in the Examples of the book.

Furthermore, it is preferable that the organic particles have a content of molecules having a weight average molecular weight of 100 or more and 10,000 or less and 1 mass% or more and 40 mass% or less. If the content of molecules having a weight average molecular weight in the above range is within the above predetermined range, in a secondary battery having an adhesive layer containing the organic particles, the adhesiveness between the electrode and the separator can be further improved. Is. Further, it is possible to further improve the output characteristics of the secondary battery manufactured using the organic particles and the battery performance such as the battery state after repeated cycles.
In the present invention, the “molecular content” is a polystyrene conversion value measured by gel permeation chromatography (GPC, solvent: tetrahydrofuran) using the measurement method described in Examples of the present specification. Can be measured.

The non-aqueous secondary battery of the present invention is preferably a wound type or a laminated type. This is because if it is a wound type or a laminated type, it is possible to further improve the adhesiveness between the battery members and further improve the output characteristics of the manufactured secondary battery and the battery state after repeated cycles.

Further, the present invention is intended to advantageously solve the above problems, the method for producing a non-aqueous secondary battery of the present invention is a method for producing any of the non-aqueous secondary battery described above. Then, the adhesive layer is formed by using the adhesive layer slurry composition containing the organic particles, and the dry amount of the adhesive layer slurry composition applied is 0.05 mg/cm ² or more and 3.0 mg/cm ² or more. It is characterized by being ² or less. As described above, by using a predetermined coating amount of the slurry composition for an adhesive layer, in the obtained secondary battery, the electrodes and the separator can be bonded with higher adhesive force. In addition, the manufactured secondary battery can exhibit higher output characteristics and a better battery state after repeated cycles.

According to the present invention, high adhesion between battery members such as electrodes and separators, good output characteristics, and a non-aqueous secondary battery capable of arranging excellent battery performance such as good battery state after repeated cycles, and A method for manufacturing the non-aqueous secondary battery can be provided.

Hereinafter, embodiments of the present invention will be described in detail.

(Non-aqueous secondary battery)
The non-aqueous secondary battery of the present invention includes at least a positive electrode, a negative electrode, a separator, and an electrolytic solution, and the separator needs to have an adhesive layer containing organic particles having a predetermined particle size. Further, at least one of the positive electrode and the negative electrode included in the non-aqueous secondary battery (I) of the present invention has a porous membrane layer in contact with the adhesive layer, and the porous membrane layer needs to have a predetermined surface roughness. To do. On the other hand, the surface of at least one of the positive electrode and the negative electrode included in the non-aqueous secondary battery (II) of the present invention, which is in contact with the adhesive layer (for example, an electrode mixture layer such as a positive electrode mixture layer and a negative electrode mixture layer). The roughness needs to be within a predetermined range.
The non-aqueous secondary battery of the present invention can be manufactured, for example, according to the method of manufacturing the non-aqueous secondary battery of the present invention.

Here, the battery members such as the positive electrode, the negative electrode, and the separator included in the non-aqueous secondary battery of the present invention are usually arranged such that the positive electrode is located on one side of the separator and the negative electrode is located on the other side of the separator. More specifically, for example, the positive electrode mixture layer side is arranged on one side of the separator and the negative electrode mixture layer side is arranged on the other side of the separator so as to face the separator side.
Further, in the non-aqueous secondary battery (I) of the present invention, as described above, at least one of the positive electrode and the negative electrode has a porous film layer in contact with the adhesive layer. In other words, in the non-aqueous secondary battery (I) of the present invention, only the positive electrode may have the porous film layer or only the negative electrode may have the porous film layer, and both the positive electrode and the negative electrode may have the porous film layer. May have a porous membrane layer. Among them, in the non-aqueous secondary battery (I) of the present invention, it is preferable that only the negative electrode has the porous film layer, and it is more preferable that the negative electrode has the porous film layers on both surfaces thereof. More specifically, it is preferable that the porous film layer is formed on the negative electrode mixture layer formed on the current collector used for the negative electrode, and the negative electrode mixture layer formed on both sides of the current collector. In the assembled secondary battery in which the porous membrane layers are respectively formed on the top, it is more preferable that the porous membrane layers and the adhesive layer are arranged so as to face each other.

On the other hand, in the non-aqueous secondary battery (II) of the present invention, as described above, at least one surface of the positive electrode and the negative electrode is in contact with the adhesive layer. In other words, in the non-aqueous secondary battery (II) of the present invention, only the surface on the positive electrode side such as the positive electrode mixture layer may be in contact with the adhesive layer, and only the surface on the negative electrode side such as the negative electrode mixture layer may be in contact. It may be in contact with the adhesive layer, or both the positive electrode side surface and the negative electrode side surface may be in contact with the adhesive layer. Among them, in the non-aqueous secondary battery (II) of the present invention, it is preferable that only the negative electrode side surface is in contact with the adhesive layer, and only the negative electrode mixture layer surface is in contact with the adhesive layer as the negative electrode side surface. It is more preferable that both surfaces of the negative electrode mixture layer are in contact with the adhesive layer. More specifically, it is preferable that the negative electrode mixture layer formed on the current collector used for the negative electrode is in contact with the adhesive layer, and the negative electrode mixture layers formed on both surfaces of the current collector are bonded to each other. In the assembled secondary battery in contact with the layer, it is more preferable that the negative electrode and the adhesive layer are arranged such that the negative electrode mixture layer and the adhesive layer face each other.

Since the non-aqueous secondary battery of the present invention has the above-mentioned predetermined adhesive layer and the surface of the predetermined porous membrane layer or electrode, the electrode and the separator arranged so as to sandwich the adhesive layer and the porous membrane layer. Excellent adhesion between and. Further, since the non-aqueous secondary battery of the present invention has the adhesive layer and the porous membrane layer or the surface of the electrode, it is possible to achieve both excellent output characteristics and a good battery state after repeated cycles.
In addition, although the case where the non-aqueous secondary battery is a lithium ion secondary battery will be described below as an example, the present invention is not limited to the following example.

<Separator>
The separator included in the non-aqueous secondary battery of the present invention needs to have an adhesive layer containing a predetermined composition. Here, in the present invention, “the separator has an adhesive layer” means that the adhesive layer is provided on the surface of the separator as the base material.
In addition, the separator as the base material for providing the adhesive layer is not particularly limited, for example, a microporous film using a polyolefin (polyethylene, polypropylene, polybutene, polyvinyl chloride) resin, polyethylene terephthalate, Microporous membrane using resin such as polycycloolefin, polyethersulfone, polyamide, polyimide, polyimideamide, polyaramid, polycycloolefin, nylon, polytetrafluoroethylene, woven or non-woven fabric using polyolefin fiber, insulation Examples thereof include aggregates of particles made of a volatile substance. Among these, it is possible to reduce the thickness of the entire separator, thereby increasing the ratio of the electrode mixture layer in the non-aqueous secondary battery and increasing the capacity per volume, A microporous membrane using a polyolefin-based (polyethylene, polypropylene, polybutene, polyvinyl chloride) resin is preferable. Of these, a microporous film made of polypropylene resin is more preferable.

<< adhesive layer >>
The adhesive layer is one member that constitutes the secondary battery included in the separator included in the non-aqueous secondary battery of the present invention. In addition, the adhesive layer contains at least organic particles, and may optionally contain an adhesive layer binder and other components other than the organic particles and the adhesive layer binder.

[Organic particles]
[[Properties of organic particles]]
-Volume average particle diameter Dp-
The volume average particle diameter Dp of the organic particles contained in the adhesive layer needs to be 0.2 μm or more and 5.0 μm or less. The volume average particle diameter Dp of the organic particles is preferably 0.3 μm or more, more preferably 0.5 μm or more, preferably 4.0 μm or less, and 0.8 μm or less. More preferable.
When the volume average particle diameter Dp of the organic particles is 0.2 μm or more, it is possible to prevent the organic particles contained in the adhesive layer in contact with the surface of the porous film layer or the electrode from entering into the irregularities on the surface of the porous film layer or the electrode surface. be able to. As a result, the adhesiveness of the organic particles can be sufficiently exhibited, and the adhesiveness between the separator and the electrode via the adhesive layer or the like can be enhanced. In addition, since it is possible to prevent the organic particles from entering the surface of the porous membrane layer or the electrode and filling the voids of the porous membrane layer or the electrode mixture layer, it is possible to prevent the deterioration of the battery resistance of the manufactured secondary battery. It is possible to suppress it and to make the secondary battery exhibit good output characteristics.
Further, when the volume average particle diameter Dp of the organic particles is 5.0 μm or less, it is possible to prevent the contact area between the organic particles and the surface of the porous membrane layer or the electrode in contact with the adhesive layer containing the organic particles from being reduced. In addition to enhancing the adhesiveness between the adhesive layer and the porous membrane layer or the electrodes, the adhesiveness between the battery members via the adhesive layer or the like can be enhanced. As a result, even when the manufactured secondary battery is repeatedly charged and discharged, the battery members are favorably adhered to each other and the expansion of the secondary battery can be suppressed. In addition, it is possible to prevent the organic particles having an excessively large particle diameter from blocking the surface of the porous membrane layer or the surface of the electrode and reducing the ion conductivity in the battery. As a result, it is possible to suppress an increase in battery resistance of the secondary battery and obtain good output characteristics.

Here, it is preferable that the volume average particle diameter Dp of the organic particles contained in the adhesive layer and the surface roughness Ra of the surface of the porous film layer or the electrode satisfy the relationship of Dp-Ra>0. In other words, the volume average particle diameter Dp of the organic particles is preferably larger than the surface roughness Ra of the surface of the porous membrane layer or the electrode.
When Dp is larger than Ra, when the adhesive layer and the porous membrane layer or the surfaces of the electrodes are adhered, the organic particles contained in the adhesive layer are prevented from entering into the irregularities of the porous membrane layer surface or the electrode surface, It is possible to prevent the organic particles from not contributing to the adhesiveness. As a result, the organic particles sufficiently contribute to the adhesiveness in the vicinity of the surface of the porous membrane layer or the surface of the electrode, and a high level between the surface of the porous membrane layer or the electrode and the battery member arranged by sandwiching the adhesive layer containing the organic particles This is because the adhesiveness can be exhibited.
Further, even when the secondary battery manufactured using the adhesive layer and the porous film layer is repeatedly charged and discharged, the high adhesiveness between the battery members is maintained well, and deterioration of the battery state such as expansion of the battery is prevented. This is because it can be suppressed.
Further, when the adhesive layer and the porous membrane layer or the surfaces of the electrodes are adhered, it is possible to prevent the organic particles from entering the gaps such as the porous membrane layer or the electrode mixture layer and filling the gaps. This is because an increase in battery resistance of the secondary battery can be suppressed and the secondary battery can exhibit good output characteristics.

-Glass transition temperature-
The glass transition temperature of the organic particles is preferably 10°C or higher, more preferably 20°C or higher, further preferably 30°C or higher, more preferably 110°C or lower, more preferably 90°C or lower, and further preferably 80°C or lower. This is because if the glass transition temperature of the organic particles is 10° C. or higher, the adhesiveness of the adhesive layer containing the organic particles can be further improved by keeping the strength of the organic particles good. Further, when the glass transition temperature of the organic particles is 110° C. or lower, the contact area between the organic particles and the surface of the porous membrane layer or the electrode in contact with the adhesive layer containing the organic particles is increased to thereby bond the adhesive layers. This is because the sex can be further improved.

-Content of low molecular weight molecules-
Further, in the organic particles, the content of molecules having a weight average molecular weight of 100 or more and 10000 or less in the organic particles is preferably 1% by mass or more, more preferably 5% by mass or more, and 10% by mass. It is more preferably at least 40% by mass, more preferably at most 35% by mass, still more preferably at most 20% by mass. This is because if the content of low-molecular weight molecules in the organic particles is at least the above lower limit, the adhesiveness of the adhesive layer containing the organic particles can be further improved by lowering the viscosity of the organic particles to some extent. Further, if the content of the low-molecular weight molecules in the organic particles is not more than the above upper limit, the adhesiveness of the adhesive layer containing the organic particles can be further improved by keeping the strength of the organic particles favorable.

[[Structure of organic particles]]
The structure of the organic particles is not particularly limited as long as it is a structure that can achieve the above-mentioned predetermined volume average particle diameter Dp, and for example, a structure in which individual polymers having a particle shape individually exist, a particle shape And a structure in which individual polymers having a particle shape are present in contact with each other, and a structure in which individual polymers having a particle shape are present as a composite.
When the individual particles are present in contact with each other or in the form of a composite, for example, a core portion having a particle shape, and a shell portion that partially covers the outer surface of the core portion and also has a particle shape are provided. The core-shell structure may be formed.
The organic particles are usually present in the form of particles in the slurry composition for an adhesive layer described below. Further, the organic particles usually exist in a particle shape even in the formed adhesive layer, but may have any other shape.

-Core shell structure-
In the core-shell structure, the core part is a part inside the shell part. The shell portion is usually the outermost portion of the organic particles. The form of the shell portion is not particularly limited, but the shell portion is preferably composed of polymer particles. When the shell part is composed of polymer particles, a plurality of particles forming the shell part may overlap in the radial direction of the organic particles. However, in the radial direction of the organic particles, it is preferable that the particles constituting the shell portion do not overlap with each other and the particles of the polymer form the shell portion with a single layer.

[[Organic particle composition]]
The composition of the organic particles is not particularly limited as long as it is a composition that can achieve the above-described predetermined volume average particle diameter Dp, and known organic particles used in an adhesive layer for a non-aqueous secondary battery can be mentioned. You can Specifically, examples of the composition of the organic particles include a water-insoluble known polymer that can be dispersed in a dispersion medium such as water, for example, a thermoplastic elastomer. Then, as the thermoplastic elastomer, a conjugated diene polymer and an acrylic polymer are preferable, and an acrylic polymer is more preferable.
Here, the conjugated diene polymer refers to a polymer containing a conjugated diene monomer unit, and specific examples of the conjugated diene polymer include aliphatic conjugated diene monomer units such as butadiene rubber (BR). A polymer containing styrene-butadiene copolymer (SBR), a polymer containing an aromatic vinyl monomer unit and an aliphatic conjugated diene monomer unit; an acrylonitrile monomer such as an acrylic rubber (NBR) Polymers containing a body unit and a butadiene monomer unit; and their hydrides and the like.
Here, the acrylic polymer refers to a polymer including a (meth)acrylic acid ester monomer unit, and may include other monomer units other than the (meth)acrylic acid ester monomer unit. The (meth)acrylic acid ester monomer unit means a structural unit having a structure formed by polymerizing a (meth)acrylic acid ester monomer.
In addition, in this invention, "(meth)acryl" means acryl and/or methacryl.

Here, examples of the (meth)acrylic acid ester monomer capable of forming the (meth)acrylic acid ester monomer unit include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate and Butyl acrylate such as t-butyl acrylate, octyl acrylate such as pentyl acrylate, hexyl acrylate, heptyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, lauryl acrylate, n-tetradecyl acrylate, stearyl acrylate, etc. And butyl methacrylate such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate and t-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate such as 2-ethylhexyl methacrylate, nonyl methacrylate. And methacrylic acid alkyl esters such as decyl methacrylate, lauryl methacrylate, n-tetradecyl methacrylate, and stearyl methacrylate. Among them, alkyl acrylate is preferable, butyl acrylate and methyl methacrylate are more preferable, and butyl acrylate is further preferable. As the (meth)acrylic acid ester monomer, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio.

Moreover, the acrylic polymer is not particularly limited as an example of a monomer capable of forming another monomer unit that can be used in combination with the (meth)acrylic acid ester monomer unit, and includes, for example, , Ethylenically unsaturated carboxylic acid monomers, vinyl cyanide-based monomers, unsaturated carboxylic acid amide monomers, hydroxyalkyl group-containing unsaturated monomers, di(meth)acrylic acid ester monomers , Allyl compound monomers, and aromatic vinyl monomers and aliphatic conjugated diene monomers other than the above-mentioned conjugated diene polymer.

Here, examples of the ethylenically unsaturated carboxylic acid monomer capable of forming the ethylenically unsaturated carboxylic acid monomer unit include, for example, acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid. And mono- or dicarboxylic acids (anhydrides) and the like. Of these, methacrylic acid is preferable. As the ethylenically unsaturated carboxylic acid monomer, one type may be used alone, or two or more types may be combined in any ratio.
Examples of the vinyl cyanide-based monomer include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethylacrylonitrile and the like. Among them, acrylonitrile and methacrylonitrile are preferable, and acrylonitrile is more preferable. In addition, these may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios.
Examples of the unsaturated carboxylic acid amide monomer include acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N,N-dimethylacrylamide, N-hydroxymethylacrylamide and the like. Especially, it is preferable to use N-hydroxymethyl acrylamide. In addition, these may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios.
Examples of the unsaturated monomer containing a hydroxyalkyl group include β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate and 3-chloro-2-. Hydroxypropyl methacrylate, di-(ethylene glycol) maleate, di-(ethylene glycol) itaconate, 2-hydroxyethyl maleate, bis(2-hydroxyethyl) maleate, 2-hydroxyethyl methyl fumarate and the like can be mentioned. In addition, these may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios.
Examples of the di(meth)acrylic acid ester monomer include ethylene dimethacrylate, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, and 1,3-butylene glycol diacrylate. In addition, these may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios.
Examples of the allyl compound monomer include allyl compounds such as allyl alcohol such as allyl glycidyl ether. In addition, these may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios. Further, the above-mentioned di(meth)acrylic acid ester monomer and allyl compound monomer may be used as a polymerizable monomer or a crosslinkable monomer in the polymerization reaction. Here, the crosslinkable monomer unit is a structural unit having a structure formed by polymerizing a crosslinkable monomer. The crosslinkable monomer is a monomer capable of forming a crosslinked structure during or after the polymerization by radicals derived from the polymerization initiator.
The aromatic vinyl monomer is not particularly limited, and examples thereof include styrene, α-methylstyrene, vinyltoluene, divinylbenzene and the like. The aromatic vinyl monomer may be used alone or in combination of two or more kinds at an arbitrary ratio.
Further, the aliphatic conjugated diene monomer is not particularly limited, and 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chloro -1,3-Butadiene, substituted linear conjugated pentadienes, substituted and side chain conjugated hexadienes and the like. The aliphatic conjugated diene monomer may be used alone or in combination of two or more kinds at an arbitrary ratio.

-Composition of core-
Here, as an example of the polymerizable monomer for the core portion used in the preparation of the organic particles in the case where the organic particles have a core-shell structure, among the above-mentioned polymerizable monomers, a (meth)acrylic acid ester monomer is used. It is preferable to use a body or a vinyl cyanide-based monomer. That is, the polymer of the core portion preferably contains a (meth)acrylic acid ester monomer unit or a vinyl cyanide-based monomer unit. Here, the polymer of the core part may contain only a (meth)acrylic acid ester monomer unit, or may contain only a vinyl cyanide-based monomer unit. The monomer unit and the vinyl cyanide-based monomer unit may be contained in combination. The vinyl cyanide-based monomer unit refers to a structural unit having a structure formed by polymerizing acrylonitrile or methacrylonitrile, for example. Thereby, the ionic conductivity of the core portion can be increased, so that when the core-shell structure is used for the organic particles, the ionic conductivity of the organic particles can be effectively increased.

Further, the polymer constituting the core part of the organic particles preferably contains a crosslinkable monomer unit. The mechanical strength of the organic particles can be increased by the polymer constituting the core portion containing the crosslinkable monomer unit. Examples of the crosslinkable monomer include the above-mentioned di(meth)acrylic acid ester monomer and allyl compound monomer. These may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios.

Further, the polymer constituting the core part of the organic particles is the above-mentioned ethylenically unsaturated carboxylic acid monomer unit, unsaturated carboxylic acid amide monomer, unsaturated monomer containing a hydroxyalkyl group, di( It may further include a (meth)acrylic acid ester monomer, and an aromatic vinyl monomer and an aliphatic conjugated diene monomer other than the above-mentioned conjugated diene polymer.

-Shell composition-
The shell portion preferably partially covers the outer surface of the core portion. That is, the shell portion covers the outer surface of the core portion, but preferably does not cover the entire outer surface of the core portion. Even if the outer surface of the core part seems to be completely covered by the shell part from the appearance, if the hole that connects the inside and the outside of the shell part is formed, the shell part will not be outside the core part. Treat as if it partially covered the surface. As described above, if the shell portion does not cover the entire outer surface of the core portion, the ions in the electrolytic solution can easily enter the core portion of the particulate polymer. Therefore, when the core portion has high ionic conductivity, it is possible to effectively utilize the high ionic conductivity.

The polymer forming the shell portion of the organic particles preferably contains the aromatic vinyl monomer unit mentioned above, and more preferably uses styrene.
The proportion of the aromatic vinyl monomer unit in the polymer constituting the shell portion is preferably 20% by mass or more, more preferably 40% by mass or more, further preferably 50% by mass or more, further preferably 60% by mass or more, It is particularly preferably 80% by mass or more, preferably 100% by mass or less, more preferably 99.5% by mass or less, and further preferably 99% by mass or less.
Further, the polymer forming the shell part of the organic particles may further include a monomer unit which may be included in the polymer forming the core part of the organic particles.

[[Polymerization method of organic particles]]
The method for polymerizing the above-mentioned monomers used for the preparation of the organic particles is not particularly limited, and for example, any method such as a solution polymerization method, a suspension polymerization method, a bulk polymerization method, or an emulsion polymerization method may be used. Good. As the polymerization reaction, addition polymerization such as ionic polymerization, radical polymerization and living radical polymerization can be used. The emulsifier, dispersant, polymerization initiator, chain transfer agent and the like used in the polymerization can be those generally used, and the amount thereof can also be the amount generally used.

For example, the emulsifier that can be used to prepare the organic particles is not particularly limited, and known emulsifiers such as anionic surfactants, nonionic surfactants, cationic surfactants and amphoteric surfactants are used. It may be either. Specific examples of anionic surfactants include sulfuric acid of higher alcohols such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecyl sulfate, ammonium dodecyl sulfate, sodium octyl sulfate, sodium decyl sulfate, sodium tetradecyl sulfate, sodium hexadecyl sulfate, and sodium octadecyl sulfate. Ester salts; sodium dodecyl diphenyl ether disulfonate, sodium succinate dialkyl ester sulfonate, sodium dodecyl benzene sulfonate, sodium lauryl benzene sulfonate, sodium hexadecyl benzene sulfonate, etc.; alkyl benzene sulfonates; sodium lauryl sulfonate, dodecyl sulfonic acid Aliphatic sulfonates such as sodium and sodium tetradecyl sulfonate; and the like, and so-called reactive emulsifiers having an unsaturated bond may be used. Above all, it is preferable to use sodium lauryl sulfate and sodium dodecylbenzenesulfonate. These may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios. They can also be used as dispersants.

Examples of the polymerization initiator include known polymerization initiators such as sodium persulfate, ammonium persulfate and potassium persulfate. Of these, ammonium persulfate and potassium persulfate are preferably used. These may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios.

The chain transfer agent is not particularly limited, and examples thereof include alkyl mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, and n-stearyl mercaptan; dimethyl. Xanthogen compounds such as xanthogen disulfide and diisopropyl xanthogen disulfide; thiuram compounds such as terpinolene, tetramethylthiuram disulfide, tetraethylthiuram disulfide and tetramethylthiuram monosulfide; 2,6-di-t-butyl-4-methylphenol Phenol compounds such as styrenated phenol; halogenated hydrocarbon compounds such as dichloromethane, dibromomethane, carbon tetrabromide; thioglycolic acid, thiomalic acid, 2-ethylhexyl thioglycolate, diphenylethylene, α-methylstyrene dimer, etc. Is mentioned. Of these, alkyl mercaptans are preferable, and t-dodecyl mercaptans are more preferable, from the viewpoint of suppressing side reactions. These may be used alone or in combination of two or more.

Further, as a method for polymerizing the organic particles having a core-shell structure, for example, a continuous multi-step method in which a polymer constituting the core portion of the previous stage is sequentially coated with a polymer constituting the shell portion of the subsequent stage An emulsion polymerization method and a multistage suspension polymerization method can be mentioned. As the multistage emulsion polymerization method, for example, a known polymerization method described in Patent Document 1 can be used. Further, as the emulsifier, the dispersant, the polymerization initiator, the chain transfer agent, etc. used in the multi-step emulsion polymerization, those generally used can be used, and the amount thereof can also be the amount generally used. it can.

Specifically, as a polymerization procedure of the multi-stage emulsion polymerization method, first, water as a solvent is mixed with a monomer forming a core part and an emulsifier, then a polymerization initiator is added, and emulsion polymerization is performed to form a core. A particulate polymer constituting the part is obtained. Further, a particulate polymer having a core-shell structure can be obtained by polymerizing the monomer forming the shell portion in the presence of the particulate polymer forming the core portion. At this time, from the viewpoint of partially covering the outer surface of the core part with the shell part, it is preferable that the monomer of the polymer of the shell part is divided into a plurality of times or continuously supplied to the polymerization system. By dividing the monomer of the polymer of the shell portion into a plurality of times or by continuously supplying, the polymer constituting the shell portion is formed into particles, and the particles are bonded to the core portion. It is possible to form a shell part that partially covers the core part.
When a monomer having a low affinity for the polymerization solvent is used as the monomer forming the polymer of the shell part, the shell part that partially covers the core part tends to be easily formed. When the polymerization solvent is water, the monomer forming the shell polymer is preferably a hydrophobic monomer, and particularly preferably an aromatic vinyl monomer as described above.
Further, if the amount of emulsifier used is reduced, it tends to be easier to form a shell part that partially covers the core part, and by appropriately adjusting the emulsifier amount, it is possible to form a shell part that partially covers the core part. it can.

When a monomer having a low affinity for the polymerization solvent is used as the monomer forming the polymer of the shell part, the shell part that partially covers the core part tends to be easily formed. When the polymerization solvent is water, the monomer forming the shell polymer is preferably a hydrophobic monomer, and particularly preferably an aromatic vinyl monomer as described above.
Further, if the amount of emulsifier used is reduced, it tends to be easier to form a shell part that partially covers the core part, and by appropriately adjusting the emulsifier amount, it is possible to form a shell part that partially covers the core part. it can.

Here, in the case of supplying the monomer of the polymer constituting the shell portion in a plurality of divided times, the amount and the amount of the individual dividedly supplied monomers in the case of dividing and supplying the monomer It is possible to control the particle diameter of the particles covered with the shell portion by the number of times and the like. Further, in the case of continuously supplying the monomer of the polymer forming the shell part, the particle diameter of the particles forming the shell part is controlled by adjusting the supply amount of the monomer per unit time. It is possible. Then, the particle size of the organic particles after forming the shell portion can be set in a desired range by adjusting the amount of the emulsifier, the amount of the monomer, and the like.
When a monomer having a low affinity for the polymerization solvent is used as the monomer forming the polymer of the shell part, the shell part that partially covers the core part tends to be easily formed. When the polymerization solvent is water, the monomer forming the shell polymer is preferably a hydrophobic monomer, and particularly preferably an aromatic vinyl monomer as described above.
Further, if the amount of emulsifier used is reduced, it tends to be easier to form a shell part that partially covers the core part, and by appropriately adjusting the emulsifier amount, it is possible to form a shell part that partially covers the core part. it can.

[Binder for adhesive layer]
Examples of the binder for the adhesive layer that can be used for forming the adhesive layer include the same compositions as those exemplified as the composition of the organic particles.

Further, as the method for polymerizing the binder for the adhesive layer, there may be mentioned the same polymerization methods as those exemplified as the method for polymerizing the organic particles, and an emulsifier, a polymerization initiator, a chain transfer agent and the like which can be used for the polymerization. The same composition and amount as those exemplified as the method for polymerizing the organic particles can be used.

[Slurry composition for adhesive layer]
The adhesive layer can be formed, for example, by applying the above-mentioned adhesive layer slurry composition containing organic particles onto the separator. Here, the adhesive layer slurry composition, in addition to containing the organic particles described above, may further contain the binder for the adhesive layer described above, and other components, in the form of a slurry with a dispersion medium such as water. It is a composition.
In addition, other components are not particularly limited, and examples thereof include a thickener, a dispersant, and a surface tension adjusting agent. Known thickeners, dispersants, surface tension adjusting agents and the like can be used.

Specifically, for example, carboxymethylcellulose sodium salt can be used as a thickener, polyacrylic acid can be used as a dispersant, and ethylene oxide- can be used as a surface tension adjusting agent dispersant. Propylene oxide copolymers can be used. These examples are not particularly limited, and as the other components, one kind may be used alone, or two kinds or more may be used in combination at an arbitrary ratio.

[[Preparation Method of Slurry Composition for Adhesive Layer]]
The slurry composition for the adhesive layer can be prepared, for example, by dissolving or dispersing the above-mentioned organic particles, the binder for the adhesive layer, and other components in a solvent such as water and/or an organic solvent. .. Specifically, a ball mill, a sand mill, a bead mill, a pigment disperser, a crusher, an ultrasonic disperser, a homogenizer, a planetary mixer, a mix such as a fill mix is used to mix the above components and the solvent. A slurry composition for an adhesive layer can be prepared.
As the solvent used for preparing the slurry composition for the adhesive layer, the solvent contained in the dispersion liquid of the binder for the adhesive layer described above may be used.

<<Formation of adhesive layer>>
The adhesive layer is formed on the separator as the base material. Here, the adhesive layer is, for example, a step of applying the above-mentioned slurry composition for an adhesive layer on a substrate (application step) and a step of drying the slurry composition for an adhesive layer applied on a substrate (drying). Process) and is formed.

[Coating process]
The method for applying the slurry composition for an adhesive layer onto a substrate is not particularly limited, and a known method can be used. Specifically, as a coating method, a doctor blade method, a dipping method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, a brush coating method or the like can be used. At this time, the adhesive layer slurry composition may be applied to only one side or both sides of the substrate, and is preferably applied to both sides. In addition, the film thickness of the slurry composition for the adhesive layer on the substrate after coating and before drying can be appropriately set according to the thickness of the adhesive layer obtained by drying.

[Drying process]
The method for drying the slurry composition for the adhesive layer on the substrate is not particularly limited, and known methods can be used, for example, hot air, hot air, low-humid air drying method, vacuum drying method, infrared ray or electron beam. And a drying method by irradiation. By thus drying the slurry composition for an adhesive layer on a substrate, an adhesive layer-attached separator having an adhesive layer formed on a substrate can be obtained.

<Electrode (negative electrode)>
The negative electrode is not particularly limited and usually includes a current collector and a negative electrode mixture layer as an electrode mixture layer formed on the current collector. In addition, the negative electrode may further include any layer other than the porous membrane layer described below on the current collector or the negative electrode mixture layer.
Here, in the electrode included in the non-aqueous secondary battery (I), at least one of the negative electrode and the positive electrode needs to have a porous film layer in contact with the adhesive layer. Further, in the negative electrode included in the non-aqueous secondary battery (I), it is preferable that at least the negative electrode mixture layer of the negative electrode has a porous film layer that is in contact with the above-mentioned adhesive layer, and the above-mentioned adhesive is formed only on the negative electrode mixture layer. It is more preferred to have a porous membrane layer in contact with the layer.
On the other hand, in the electrode included in the non-aqueous secondary battery (II), at least one surface of the negative electrode and the positive electrode must be in contact with the adhesive layer and have a surface roughness Ra of 0.1 μm or more and 5.0 μm or less. .. Further, in the electrode included in the non-aqueous secondary battery (II), at least the surface on the negative electrode side preferably contacts the adhesive layer, more preferably the negative electrode mixture layer contacts the adhesive layer, and the negative electrode mixture layer It is preferable that the surface on the negative electrode side such as has a surface roughness Ra of 0.1 μm or more and 5.0 μm or less.
Then, the negative electrode mixture layer is not particularly limited, for example, a negative electrode slurry composition obtained by dispersing the negative electrode active material and any binder and the like in a solvent is applied onto a current collector, It can be formed by drying.

<<Current collector>>
Here, a material having electrical conductivity and electrochemical durability is used as the current collector. Specifically, as the current collector, for example, a current collector made of a metal material such as iron, copper, aluminum, nickel, stainless steel, titanium, tantalum, gold, or platinum can be used. The above materials may be used alone or in combination of two or more at an arbitrary ratio. Above all, a thin film made of copper is preferable as the current collector used for producing the negative electrode.

<<Negative electrode active material>>
The negative electrode active material is a material that transfers and receives electrons in the electrode of the secondary battery. Then, as the negative electrode active material for the lithium ion secondary battery, a material capable of inserting and extracting lithium is usually used. Further, the negative electrode active material is not particularly limited, and examples thereof include a carbon-based negative electrode active material, a metal-based negative electrode active material, and a negative electrode active material in which these are combined.

Examples of the carbonaceous material include easily graphitizable carbon and non-graphitizable carbon having a structure close to an amorphous structure represented by glassy carbon.
Here, examples of the graphitizable carbon include a carbon material obtained from tar pitch obtained from petroleum or coal as a raw material. Specific examples include coke, mesocarbon microbeads (MCMB), mesophase pitch carbon fibers, and pyrolytic vapor growth carbon fibers.
Examples of the non-graphitizable carbon include phenol resin fired bodies, polyacrylonitrile-based carbon fibers, pseudo-isotropic carbon, furfuryl alcohol resin fired bodies (PFA), and hard carbon.

Furthermore, examples of the graphite material include natural graphite and artificial graphite.
Here, as the artificial graphite, for example, artificial graphite obtained by heat-treating carbon containing easily graphitizable carbon mainly at 2800° C. or higher, graphitized MCMB obtained by heat-treating MCMB at 2000° C. or higher, and mesophase pitch-based carbon fiber at 2000° C. Examples include the graphitized mesophase pitch-based carbon fiber heat-treated as described above.

In addition, the metal-based negative electrode active material is an active material containing a metal, and usually has a structure including an element capable of inserting lithium, and the theoretical electric capacity per unit mass when lithium is inserted is 500 mAh/ An active material having a weight of at least g. Examples of the metal-based active material include, for example, lithium metal and simple metals capable of forming a lithium alloy (for example, Ag, Al, Ba, Bi, Cu, Ga, Ge, In, Ni, P, Pb, Sb, Si, Sn). , Sr, Zn, Ti, etc.) and alloys thereof, and their oxides, sulfides, nitrides, silicides, carbides, phosphides and the like. Among these, as the metal-based negative electrode active material, an active material containing silicon (silicon-based negative electrode active material) is preferable. This is because it is possible to increase the capacity of the lithium-ion secondary battery by using the silicon-based negative electrode active material.

Examples of the silicon-based negative electrode active material include silicon (Si), alloys containing silicon, SiO, SiO _x , and a compound of Si-containing material and conductive carbon obtained by coating or compounding Si-containing material with conductive carbon. And so on. These silicon-based negative electrode active materials may be used alone or in combination of two or more.
Among them, as the negative electrode active material, a carbon-based active material is preferable, a graphite material is more preferable, and artificial graphite is further preferable.

<<Slurry composition for negative electrode>>
The negative electrode slurry composition can be prepared, for example, by dispersing the above-described negative electrode active material and any binder in a solvent, and the dispersion method includes, for example, preparation of an adhesive layer slurry composition. A method similar to the method can be used.

<<Method of forming negative electrode mixture layer>>
The negative electrode mixture layer includes, for example, a step of applying the above-described negative electrode slurry composition on a current collector (application step) and a step of drying the negative electrode slurry composition applied on the current collector (drying step). ) And is formed.

[Coating process]
The method for applying the slurry composition for the negative electrode on the current collector is not particularly limited, and a known method can be used. Specifically, as a coating method, a doctor blade method, a dipping method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, a brush coating method or the like can be used. At this time, the negative electrode slurry composition may be applied to only one surface of the current collector, or may be applied to both surfaces thereof. The thickness of the slurry film on the current collector after coating and before drying can be appropriately set according to the thickness of the negative electrode mixture layer obtained by drying.

[Drying process]
The method for drying the negative electrode slurry composition on the current collector is not particularly limited, and known methods can be used, for example, hot air, hot air, low humidity air drying method, vacuum drying method, infrared ray or electron beam. And a drying method by irradiation. By drying the negative electrode slurry composition on the current collector in this manner, a negative electrode mixture layer is formed on the current collector, and a negative electrode for a secondary battery including the current collector and the negative electrode mixture layer is formed. Obtainable.

After the drying step, the negative electrode mixture layer may be subjected to a pressure treatment using a die press or a roll press. The pressure treatment can improve the adhesiveness between the negative electrode mixture layer and the current collector. Further, when the negative electrode mixture layer contains a curable polymer, it is preferable to cure the polymer after forming the negative electrode mixture layer.

<Electrode (positive electrode)>
The positive electrode is not particularly limited, and generally includes a current collector and a positive electrode mixture layer as an electrode mixture layer formed on the current collector. Further, the positive electrode may further include any layer other than the porous membrane layer described later on the current collector or the positive electrode mixture layer. Here, in the electrode included in the non-aqueous secondary battery (I), the positive electrode Alternatively, at least one of the negative electrodes needs to have a porous membrane layer in contact with the adhesive layer, and the positive electrode mixture layer can have a porous membrane layer in contact with the adhesive layer described above.
On the other hand, in the electrode included in the non-aqueous secondary battery (II), at least one surface of the positive electrode and the negative electrode must be in contact with the adhesive layer and have a surface roughness Ra of 0.1 μm or more and 5.0 μm or less. .. In the electrode included in the non-aqueous secondary battery (II), the positive electrode mixture layer of the positive electrode may be in contact with the adhesive layer and have a surface roughness Ra of 0.1 μm or more and 5.0 μm or less.
The positive electrode mixture layer is not particularly limited, and may be, for example, a positive electrode slurry composition obtained by dispersing a positive electrode active material, a conductive material, and an arbitrary binder in a solvent on a current collector. It can be formed by coating and drying. As the current collector, the same current collectors as those exemplified as the current collector used for the negative electrode can be used. Above all, a thin film made of aluminum is preferable as the current collector used for producing the positive electrode.
Here, as the conductive material and the binder in the positive electrode mixture layer, known materials can be used, for example, those described in JP2013-145763A can be used. The method for forming the positive electrode mixture layer on the current collector is not particularly limited, and the same method as the above-described method for forming the negative electrode mixture layer can be mentioned.

The positive electrode active material is not particularly limited, and lithium-containing cobalt oxide (LiCoO ₂ ), lithium manganate (LiMn ₂ O ₄ ), lithium-containing nickel oxide (LiNiO ₂ ), Co-Ni-Mn lithium-containing composite oxide (Li (Co Mn Ni) O 2), lithium-containing composite oxide of Ni-Mn-Al, lithium-containing composite oxide of Ni-Co-Al, olivine-type phosphate Lithium iron (LiFePO ₄ ), olivine-type lithium manganese phosphate (LiMnPO ₄ ), Li ₂ MnO ₃ —LiNiO ₂ based solid solution, lithium represented by Li _1+x Mn _2-x O ₄ (0<X<2) Examples of known positive electrode active materials include excess spinel compounds, Li[Ni _0.17 Li _0.2 Co _0.07 Mn _0.56 ]O ₂ , and LiNi _0.5 Mn _1.5 O ₄ .
The amount and particle size of the positive electrode active material are not particularly limited and may be the same as those of conventionally used positive electrode active materials.

<< porous membrane layer >>
The porous membrane layer is a layer included in at least one of the positive electrode and the negative electrode included in the non-aqueous secondary battery (I) of the present invention, and is in contact with the above-mentioned adhesive layer in the structure of the secondary battery. Further, the porous membrane layer used in the non-aqueous secondary battery (I) needs to have a predetermined surface roughness Ra. Here, the porous membrane layer is preferably formed at least on the negative electrode, more preferably formed only on the negative electrode, and further preferably formed on both surfaces of the negative electrode. Specifically, the porous membrane layer is preferably formed at least on the negative electrode mixture layer, more preferably formed only on the negative electrode mixture layer, and formed on both surfaces of the current collector. More preferably, it is formed on each material layer.

[Surface roughness Ra]
The surface roughness Ra of the porous membrane layer needs to be 0.1 μm or more and 5.0 μm or less. The surface roughness Ra of the porous membrane layer is preferably 0.15 μm or more, more preferably 0.2 μm or more, preferably 1.0 μm or less, and 0.6 μm or less. More preferable.
When the surface roughness Ra of the porous membrane layer is 0.1 μm or more, the contact area between the porous membrane layer and the adhesive layer in contact with the porous membrane layer is increased, so that the adhesion between the porous membrane layer and the adhesive layer is increased. In addition to improving the adhesiveness, it is possible to enhance the adhesiveness between the electrode and the separator through the porous membrane layer and the adhesive layer. As a result, good adhesion between battery members can be maintained even when the manufactured secondary battery is repeatedly charged and discharged, and the expansion of the secondary battery can be suppressed.
When the surface roughness Ra of the porous film layer is 5.0 μm or less, the organic particles contained in the adhesive layer enter the irregularities of the porous film layer when the porous film layer and the adhesive layer are bonded together. Thus, it can be suppressed that the adhesiveness is not contributed. As a result, the adhesiveness of the organic particles can be sufficiently exhibited, and the adhesiveness between the battery members via the porous membrane layer and the adhesive layer can be enhanced. In addition, since it is possible to prevent the organic particles from entering the porous film layer and filling the voids in the porous film layer, it is possible to suppress an increase in the battery resistance of the manufactured secondary battery, and to provide a good output to the secondary battery. The characteristics can be exhibited.

Here, the porous membrane layer is not particularly limited as long as it satisfies the above-mentioned surface roughness Ra, and may have any composition capable of forming a non-aqueous secondary battery. For example, the porous membrane layer preferably contains non-conductive particles that can enhance the heat resistance and/or strength of the battery member, and further contains a binder for the porous membrane layer and the like in addition to the non-conductive particles. You can

[Non-conductive particles]
The non-conductive particles are not particularly limited as long as they are non-conductive particles that can achieve the above-described predetermined surface roughness Ra, and known non-conductive particles used in the porous membrane layer can be mentioned. .. Specifically, for example, inorganic fine particles can be used as the non-conductive particles. As the non-conductive particles, both the inorganic fine particles and organic fine particles other than the binder for the porous film layer described later can be used, but usually only the inorganic fine particles are used. Among them, the material of the non-conductive particles is preferably a material that stably exists in the environment where the non-aqueous secondary battery is used and is electrochemically stable. From this point of view, preferable examples of the material of the non-conductive particles include aluminum oxide (alumina), hydrated aluminum oxide (boehmite), silicon oxide, magnesium oxide (magnesia), calcium oxide, titanium oxide (titania). , BaTiO ₃ , ZrO, oxide particles such as alumina-silica composite oxide; nitride particles such as aluminum nitride and boron nitride; covalent bond crystal particles such as silicon and diamond; barium sulfate, calcium fluoride, barium fluoride. And the like, such as sparingly soluble ionic crystal particles; clay fine particles such as talc and montmorillonite; Further, these particles may be subjected to element substitution, surface treatment, solid solution treatment or the like, if necessary.
The above-mentioned non-conductive particles may be used alone or in combination of two or more.

[Binder for porous membrane layer]
[[Composition of Binder for Porous Membrane Layer]]
The composition that can be used in the binder for the porous membrane layer that can be included in the porous membrane layer is not particularly limited as long as it has a binding function, and preferably includes a polymer. Further, the polymer is not particularly limited, and the same monomer as the polymerizable monomer of the polymers mentioned above as the polymer suitable for forming the organic particles may be used. You can
In addition, the composition of the binder for the porous membrane layer is preferably prepared in the same composition as the binder for the adhesive layer that contacts each other in the structure of the secondary battery. If the binder for the porous membrane layer and the binder for the adhesive layer have the same composition, when the secondary battery has a configuration in which the porous membrane layer and the adhesive layer are in direct contact, the porous membrane layer and the adhesive layer This is because the layers can be bound with higher adhesive strength. As a result, the adhesiveness between the electrode members via the porous membrane layer and the adhesive layer can be further enhanced.
The reason why the binder for the porous membrane layer has the same composition as the binder for the adhesive layer to further improve the adhesiveness between the battery members is not clear, but it is presumed as follows. It
That is, in the structure of the secondary battery, the porous membrane layer and the adhesive layer that are in direct contact with each other have the same binder component, so that the porous membrane layer and the adhesive layer can be easily integrated with good compatibility. As a result, the porous membrane layer and the adhesive layer are in contact with the electrode and the separator, respectively, in a well integrated state. The electrodes and the separators arranged so as to sandwich the porous membrane layer and the adhesive layer in this manner can be more firmly adhered to each other by, for example, hot pressing in the battery manufacturing process.

[[Polymerization method]]
The method for polymerizing the binder for the porous membrane layer is not particularly limited, and the same method as the above-mentioned method for polymerizing the organic particles can be mentioned.

[Slurry composition for porous membrane layer]
Here, the porous membrane layer can be formed, for example, by applying the above-mentioned slurry composition for a porous membrane layer containing the non-conductive particles onto a substrate such as an electrode. Here, the slurry composition for the porous membrane layer, in addition to containing the non-conductive particles described above, may further contain the binder for the porous membrane layer described above, and other components, a dispersion medium such as water. It is preferable that the composition is in the form of a slurry.
In addition, other components are not particularly limited, and examples thereof include the same thickeners, dispersants, and surface tension adjusting agents as those exemplified as the other components that can be used in the adhesive layer slurry composition. be able to.
Then, the slurry composition for the porous membrane layer is obtained by dissolving or dispersing the above-mentioned non-conductive particles, the binder for the porous membrane layer, and other components in a solvent such as water and/or an organic solvent. Can be prepared by Here, as the method for preparing the slurry composition for the porous film layer, for example, the same method as the method for preparing the slurry composition for the adhesive layer described above can be used.

[Formation of porous membrane layer]
And a porous membrane layer can be provided on the positive electrode and/or the negative electrode as a base material. Further, the porous membrane layer is preferably provided on the porous membrane layer formed on the negative electrode as the base material.
The method for forming the porous membrane layer can be applied, for example, through the same coating step and drying step as those exemplified as the method for forming the adhesive layer. Then, the film thickness of the slurry composition for a porous membrane layer on the substrate after coating and before drying can be appropriately set according to the thickness of the porous membrane layer obtained by drying.
Thus, the positive electrode with a porous membrane layer and/or the negative electrode with a porous membrane layer in which the porous membrane layer is formed on the electrode is obtained by applying and drying the slurry composition for the porous membrane layer on the electrode as the base material. be able to.

<Electrolyte>
As the electrolytic solution, an organic electrolytic solution prepared by dissolving a supporting electrolyte in an organic solvent is usually used. For example, when the non-aqueous secondary battery is a lithium ion secondary battery, a lithium salt is used as the supporting electrolyte. Examples of the lithium salt include LiPF ₆ , LiAsF ₆ , LiBF ₄ , LiSbF ₆ , LiAlCl ₄ , LiClO ₄ , CF ₃ SO ₃ Li, C ₄ F ₉ SO ₃ Li, CF ₃ COOLi, (CF ₃ CO) ₂ NLi. , (CF ₃ SO ₂ ) ₂ NLi, (C ₂ F ₅ SO ₂ )NLi, and the like. Among them, LiPF ₆ , LiClO ₄ , and CF ₃ SO ₃ Li are preferable, and LiPF ₆ is particularly preferable, because it is easily dissolved in a solvent and exhibits a high dissociation degree. The electrolyte may be used alone or in combination of two or more at an arbitrary ratio. Usually, the higher the dissociation degree of the supporting electrolyte, the higher the lithium ion conductivity tends to be, so the lithium ion conductivity can be adjusted by the type of the supporting electrolyte.

The organic solvent used in the electrolytic solution is not particularly limited as long as it can dissolve the supporting electrolyte, and examples thereof include dimethyl carbonate (DMC), ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC). ), butylene carbonate (BC), ethyl methyl carbonate (EMC) and other carbonates; γ-butyrolactone, methyl formate and other esters; 1,2-dimethoxyethane, tetrahydrofuran and other ethers; sulfolane, dimethyl sulfoxide and the like. Sulfur compounds; and the like are preferably used. Further, a mixed solution of these solvents may be used. Among them, carbonates are preferably used because they have a high dielectric constant and a wide stable potential region, and it is more preferable to use a mixture of ethylene carbonate and ethyl methyl carbonate.
Further, known additives such as vinylene carbonate (VC), fluoroethylene carbonate (FEC), ethyl methyl sulfone and the like may be added to the electrolytic solution.

<Structure of secondary battery>
The non-aqueous secondary battery of the present invention is preferably a wound type or a laminated type, more preferably a wound type. If it is a wound type or a laminated type, since the electrodes and the separator are satisfactorily hot pressed with the adhesive layer and the porous membrane layer sandwiched therebetween in the battery manufacturing process, the adhesiveness between the battery members can be further improved. Because.

(Method for manufacturing non-aqueous secondary battery)
Any of the non-aqueous secondary batteries described above can be manufactured, for example, by using the method for manufacturing a non-aqueous secondary battery of the present invention.
Here, in the method for producing a non-aqueous secondary battery of the present invention, the adhesive layer is formed using the above-described adhesive layer slurry composition containing organic particles. Further, in the method for producing a non-aqueous secondary battery of the present invention, the applied amount of the dried product of the slurry composition for an adhesive layer is 0.05 mg/cm ² or more and 3.0 mg/cm ² or less. The coating amount of the dried adhesive layer slurry composition is preferably 0.1 mg/cm ² or more, more preferably 0.2 mg/cm ² or more, and 2.0 mg/cm ² or less. It is preferable that the amount is 0.4 mg/cm ² or less. When the coating amount of the dried adhesive layer slurry composition is at least the above lower limit, a sufficient amount of the adhesive layer contributes to further improve the adhesion between the electrode and the separator through the adhesive layer or the like. Because you can. As a result, the life of the battery can be improved without expansion and deterioration of the battery even after repeated cycles of the manufactured secondary battery. Further, when the coating amount of the dried slurry composition for an adhesive layer is at most the above upper limit, it is possible to prevent the adhesive layer from being applied in an excessive amount, and to maintain the low battery resistance that the porous membrane layer can contribute to. This is because the output characteristics of the secondary battery can be further improved.
Then, in the non-aqueous secondary battery manufactured according to the method for manufacturing a non-aqueous secondary battery of the present invention, an adhesive layer containing at least organic particles is provided on the separator. Further, in the non-aqueous secondary battery (I) produced according to the method for producing a non-aqueous secondary battery of the present invention, the porous membrane layer in contact with the adhesive layer is provided on the electrode, and the surface roughness of the porous membrane layer is Ra and the volume average particle diameter Dp of the organic particles satisfy a predetermined range. Furthermore, in the non-aqueous secondary battery (II) manufactured according to the method for manufacturing a non-aqueous secondary battery of the present invention, the surface roughness Ra of the surface of the electrode in contact with the adhesive layer and the volume average particle diameter Dp of the organic particles are predetermined. It meets the range. Therefore, the non-aqueous secondary battery (I) and the non-aqueous secondary battery (II) manufactured according to the method for manufacturing a non-aqueous secondary battery have both excellent output characteristics and a good battery state after repeated cycles. You can

Further, the method for manufacturing the non-aqueous secondary battery of the present invention can be manufactured by using a known assembly method without any particular limitation. Specifically, in the method for producing a non-aqueous secondary battery of the present invention, for example, the electrode and the separator obtained above are wound into a battery shape via an adhesive layer or the like, if necessary, by folding or the like. A secondary battery can be manufactured by putting it in a battery container, injecting an electrolytic solution into the battery container, and sealing the container. Here, in order to prevent the rise of the internal pressure of the non-aqueous secondary battery and the occurrence of overcharging/discharging, a fuse, an overcurrent preventing element such as a PTC element, an expanded metal, a lead plate, etc. are provided as necessary. May be. Further, the shape of the secondary battery may be, for example, a coin type, a button type, a sheet type, a cylindrical type, a prismatic type, a flat type or the like.

Hereinafter, the present invention will be specifically described based on Examples, but the present invention is not limited to these Examples. In the following description, "%" and "parts" representing amounts are based on mass unless otherwise specified.
Then, the volume average particle diameter Dp of the organic particles for the adhesive layer, the glass transition temperature, and the content rate of molecules having a weight average molecular weight of 100 or more and 10000 or less, the surface roughness Ra of the surface of the porous membrane layer or the electrode, the electrode member ( The adhesion between the electrodes and the separator), the low-temperature output characteristics of the secondary battery, and the state of the secondary battery after repeated cycles were calculated, measured, and evaluated by the following methods.

<Volume average particle diameter Dp>
The volume average particle diameter Dp of the organic particles for the adhesive layer was measured using a laser diffraction method. Specifically, a laser dispersion type particle size distribution measuring device (manufactured by Beckman Coulter, product name "LS-230") is prepared by using the prepared aqueous dispersion solution containing organic particles (solid content concentration 0.1% by mass) as a sample. In the particle size distribution (volume basis) obtained according to (1), the volume average particle diameter Dp (μm) was obtained as the particle diameter at which the cumulative volume calculated from the small diameter side was 50%. The results are shown in Table 1.

<Glass transition temperature>
The glass transition temperature of the organic particles for the adhesive layer was measured using a differential thermal analysis analyzer (manufactured by SII Nanotechnology Inc., product name “EXSTAR DSC6220”). Specifically, the prepared organic particles were dried at a temperature of 130° C. for 1 hour to prepare a sample. 10 mg of the obtained sample was put into an aluminum pan and weighed. An empty aluminum pan was used as the reference substance. The said sample was put into the said differential-thermal-analysis measuring device, it measured in the temperature range -100 degreeC-500 degreeC (temperature rising rate 10 degree-C/min), and the differential scanning calorimetry (DSC) curve was obtained. In addition, the said measurement followed the method prescribed|regulated to JISZ8703. In the temperature rising process, in the obtained DSC curve, the baseline immediately before the endothermic peak at which the differential signal (DDSC) becomes 0.05 mW/min/mg or more and the inflection point that first appears after the endothermic peak The temperature corresponding to the intersection with the tangent line was determined as the glass transition temperature (°C). The results are shown in Table 1.

<Molecular content>
The content of molecules having a weight average molecular weight of 100 or more and 10000 or less in the organic particles for the adhesive layer was measured using gel permeation chromatography (GPC). Specifically, the prepared dispersion liquid containing organic particles was cast on a petri dish made of a fluororesin and left standing at a temperature of 25° C. for 48 hours for drying to obtain a powder or a dry film. When powder was obtained by the drying, the powder was pressed at a temperature of 200° C. and a pressure of 5 MPa for 1 minute to obtain a film of organic particles.
Next, 0.1 g of the obtained film of organic particles was dissolved in 25 mL of tetrahydrofuran. After adjusting the solid concentration of the organic particles dissolved in tetrahydrofuran to be about 0.5 g/L, the tetrahydrofuran solution was gently filtered with a filter having an opening of 0.45 μm to give a measurement sample. Prepared.
Then, from the ratio of the peak area in the distribution curve of the weight average molecular weight obtained by measuring the prepared measurement sample under the following conditions, the content rate (% by mass) of molecules having a predetermined weight average molecular weight was calculated. .. The results are shown in Table 1.
<<Measurement conditions>>
GPC device: manufactured by Tosoh Corporation, product name "HLC-8320 GPC"
Column: manufactured by Tosoh Corporation, product name "TSKgel α-M" x 2 (φ7.8 mm ID x 30 cm x 2)
Eluent: Tetrahydrofuran Flow rate: 0.5 mL/min Sample concentration: Approximately 0.5 g/L (solid concentration)
Injection volume: 200 μL
Column temperature: 40°C
Detector: Differential refractive index detector RI (manufactured by Tosoh Corporation, product name "HLC-8320 GPC RI")
Detector condition: Pol(+), Res(1.0s)
Standard substance: Standard polystyrene kit (manufactured by Tosoh Corporation, product name "PStQuick Kit-H")

<Surface roughness Ra>
The surface roughness Ra of the formed porous film layer or the negative electrode mixture layer as the surface of the electrode was set by setting the porous film layer attached to a slide glass, and a nanoscale hybrid microscope (manufactured by KEYENCE CORPORATION, product name "VN-8010") was used. ) Was used to measure the roughness curve at a magnification of 100 times at a temperature of 25°C. In addition, in Examples 1-5, Examples 7-10, and Comparative Examples 1-2, the surface roughness of the porous membrane layer was measured, and in Example 6, the surface roughness of the negative electrode mixture layer was measured. The results are shown in Table 1.

<Adhesion between battery members>
The adhesion between the battery members (electrode and separator) was measured as peel strength as follows. Specifically, each of the produced electrode and separator was cut into a width of 10 mm and a length of 50 mm. At this time, in Examples 1 to 3, Example 5, Examples 7 to 10 and Comparative Examples 1 and 2, the porous film layer was formed on the negative electrode mixture layer of the negative electrode (the negative electrode with the porous film layer). ). Further, in Example 4, the porous film layer was formed on the positive electrode mixture layer of the positive electrode (the positive electrode with the porous film layer). Furthermore, in Example 6, the porous film layer was not formed on any of the positive electrode, the negative electrode, and the separator.
Next, in Example 1-3, Example 5, Example 7-10, and Comparative Examples 1-2, the cut-out electrode and separator were used as a porous film layer and an adhesive layer formed on the negative electrode mixture layer. In Example 4, so that the porous membrane layer formed on the positive electrode mixture layer and the adhesive layer face each other, and in Example 6, so that the negative electrode mixture layer and the adhesive layer face each other. The test pieces in which the negative electrode and the separator, or the positive electrode and the separator were integrated respectively were obtained by stacking the two on a roll press at a temperature of 80° C. and a load of 10 kN/m.
A cellophane tape was attached to the surface of the current collector with the electrode (current collector) side of the obtained test piece facing down. At this time, the cellophane tape specified in JIS Z1522 was used, and the cellophane tape was fixed to a horizontal test stand. Then, one end of the test piece on the separator side was pulled in the vertical direction at a speed of 50 mm/min to peel off, and the stress was measured. The same measurement was performed 3 times, and the average value of the measurement results was taken as the peel strength, and the adhesiveness was judged according to the following criteria. The larger the peel strength value, the higher the adhesion between the battery members. The results are shown in Table 1.
A: Peel strength is 20 N/m or more B: Peel strength is 15 N/m or more and less than 20 N/m C: Peel strength is 10 N/m or more and less than 15 N/m D: Peel strength is 5 N/m or more and less than 10 N/m E: Peel strength is less than 5N/m

<Low temperature output characteristics>
The manufactured 800 mAh wound type lithium ion secondary battery was allowed to stand for 24 hours in an environment of 25°C. Then, in a 25° C. environment, a charging operation was performed for 5 hours at a charging rate of 0.1 C, and the voltage V ₀ after the charging operation was measured.
Next, under a -10°C environment, a discharge operation was performed at a discharge rate of 1C, and the voltage V ₁ was measured 15 seconds after the start of discharge. Then, the voltage change ΔV was calculated by the formula of ΔV=V ₀ −V ₁ . The smaller the value of the voltage change ΔV, the better the low temperature output characteristics of the secondary battery. The results are shown in Table 1.
A: Voltage change ΔV is less than 350 mV B: Voltage change ΔV is 350 mV or more and less than 400 mV C: Voltage change ΔV is 400 mV or more and less than 450 mV D: Voltage change ΔV is 450 mV or more and less than 550 mV E: Voltage change ΔV is 550 mV or more

<Battery condition after repeated cycles>
The battery state after repeated cycles was evaluated by calculating the swelling rate of the battery before and after the cycle. Specifically, the manufactured 800 mAh wound type lithium ion secondary battery was allowed to stand for 24 hours in an environment of 25°C. Then, it was charged to 4.35 V at a rate of 0.1 C in an environment of 25°C. Next, the secondary battery after charging was discharged to 2.75 V at a rate of 0.1 C to perform an initial charge/discharge (cycle) operation. Then, the thickness of the central portion of the secondary battery after the initial charge and discharge was measured using a caliper to obtain the initial battery thickness T ₀ .
Subsequently, under a 45° C. environment, charging/discharging was repeated 100 cycles under the same conditions as described above. The thickness of the central portion of the secondary battery after 100 cycles was measured using a caliper, and the swelling rate T ₁ after repeated cycles was determined. Then, the swelling rate ΔT of the battery was calculated by ΔT=T ₁ /T ₀ ×100(%). The smaller the swelling rate ΔT of the battery, the better the battery state of the lithium ion secondary battery after repeated cycles, and the longer the life of the secondary battery. The results are shown in Table 1.
A: Capacity retention rate ΔT is less than 5% B: Capacity retention rate ΔT is 5% or more and less than 7% C: Capacity retention rate ΔT is 7% or more and less than 10% D: Capacity retention rate ΔT is 10% or more and less than 15% E : Capacity retention rate ΔT is 15% or more

(Example 1)
<Preparation of formation of porous membrane layer>
<<Preparation of Binder for Porous Membrane Layer>>
In a reactor equipped with a stirrer, 70 parts of ion-exchanged water, 0.15 part of sodium lauryl sulfate (manufactured by Kao Chemical Co., product name "Emar 2F") as an emulsifier, and 0.5 part of ammonium persulfate as a polymerization initiator. Each was supplied, the gas phase part was replaced with nitrogen gas, and the temperature was raised to 60°C.
On the other hand, in another container, 50 parts of ion-exchanged water, 0.5 part of sodium dodecylbenzenesulfonate as an emulsifier, 94 parts of butyl acrylate as a polymerizable monomer, 2 parts of acrylonitrile, 2 parts of methacrylic acid, N-hydroxymethylacrylamide. 1 part and 1 part of allyl glycidyl ether were supplied and mixed to obtain a monomer mixture. The monomer mixture was continuously added to the reactor for 4 hours to carry out polymerization. The polymerization reaction was continued at a temperature of 60° C. during the addition of the monomer mixture. After the addition was completed, the polymerization reaction was completed by further stirring at a temperature of 70° C. for 3 hours to prepare an aqueous dispersion containing an acrylic polymer as a binder for the porous membrane layer.

<<Preparation of Slurry Composition for Porous Membrane Layer>>
Alumina (manufactured by Sumitomo Chemical Co., Ltd., product name “AKP3000”) as non-conductive particles is 100 parts by mass in terms of solid content, 10 parts by mass of the binder for porous membrane layer obtained above, and a thickener. 5 parts by mass of carboxymethyl cellulose sodium salt (product name “MAC350HC” manufactured by Nippon Paper Industries Co., Ltd.) as a mixture with 1 part of polyacrylic acid as a dispersant using a ball mill to form a slurry for a porous membrane layer. A composition was prepared.

<Preparation of formation of adhesive layer>
<<Preparation of Organic Particles for Adhesive Layer>>
In a 5 MPa pressure resistant container equipped with a stirrer, 60 parts of methyl methacrylate as a polymerizable monomer, 35 parts of butyl acrylate, 4 parts of methacrylic acid and 1 part of ethylene glycol dimethacrylate, 1 part of sodium dodecylbenzenesulfonate as an emulsifier, ion exchange 150 parts of water and 0.5 part of potassium persulfate as a polymerization initiator were added, sufficiently stirred, and then heated to 60° C. to start polymerization. When the polymerization conversion rate reached 96%, the polymerization reaction was stopped by cooling to prepare an aqueous dispersion containing organic particles (acrylic polymer) for adhesion.
Then, the volume average particle diameter Dp of the obtained organic particles, the glass transition temperature, and the content rate of molecules having a weight average molecular weight of 100 or more and 10000 or less were measured. The results are shown in Table 1.

<<Preparation of binder for adhesive layer>>
In a reactor equipped with a stirrer, 70 parts of ion-exchanged water, 0.15 part of sodium lauryl sulfate (manufactured by Kao Chemical Co., product name "Emar 2F") as an emulsifier, and 0.5 part of ammonium persulfate as a polymerization initiator. Each was supplied, the gas phase part was replaced with nitrogen gas, and the temperature was raised to 60°C.
On the other hand, in another container, 50 parts of ion-exchanged water, 0.5 part of sodium dodecylbenzenesulfonate as an emulsifier, 94 parts of butyl acrylate as a polymerizable monomer, 2 parts of acrylonitrile, 2 parts of methacrylic acid, N-hydroxymethylacrylamide. 1 part and 1 part of allyl glycidyl ether were supplied and mixed to obtain a monomer mixture. The monomer mixture was continuously added to the reactor for 4 hours to carry out polymerization. The polymerization reaction was continued at a temperature of 60° C. during the addition of the monomer mixture. After the addition was completed, the reaction was further stirred at a temperature of 70° C. for 3 hours to complete the polymerization reaction, and an aqueous dispersion containing an acrylic polymer was prepared as a binder for the adhesive layer.

<<Preparation of Slurry Composition for Adhesive Layer>>
100 parts by mass of the organic particles for the adhesive layer obtained above in a solid content and 22 parts by mass of the binder for the adhesive layer obtained above were mixed in a stirring container to obtain a mixture. Further, to 100 parts by mass of the solid content of the organic particles, 1 part of ethylene oxide-propylene oxide copolymer as a surface tension adjusting agent was added, and further diluted with ion-exchanged water to obtain a solid content concentration of 30%. A slurry composition for an adhesive layer was obtained.

<Preparation of separator with adhesive layer>
On the separator (made of polypropylene, product name “Celgard 2500”) as a base material, the coating composition of the slurry composition for an adhesive layer obtained above was 0.3 mg/cm ² And was dried at 50° C. for 3 minutes. By performing this operation on both surfaces of the separator base material, an adhesive layer-attached separator in which adhesive layers were formed on both surfaces of the separator base material was obtained.

<Production of negative electrode>
<<Preparation of Binder for Negative Electrode>>
61.5 parts of styrene as a polymerizable monomer, 35 parts of 1,3-butadiene, and 3.5 parts of itaconic acid, 0.25 part of t-dodecyl mercaptan as a chain transfer agent, and 0.35 part of sodium lauryl sulfate as an emulsifier. The mixed solution of was added from the container containing the mixed solution to another pressure resistant container. Simultaneously with the addition, 1 part of potassium persulfate as a polymerization initiator was added to the pressure vessel to start the polymerization reaction. The polymerization reaction temperature was maintained at 75°C.
Five and a half hours after the start of the polymerization, the addition of all of the above monomers was completed, and then the temperature was further raised to 85° C. and the polymerization reaction was continued for 6 hours.
A mixture containing a particulate polymer was obtained by cooling and stopping the reaction when the polymerization conversion rate reached 97%. A 5% aqueous sodium hydroxide solution was added to the obtained mixture containing the particulate polymer to adjust the mixture to pH 8. Then, the unreacted monomers were removed by heating under reduced pressure. Further, after cooling, an aqueous dispersion (solid content concentration: 40%) containing a styrene-butadiene copolymer as a binder for the negative electrode was obtained.

<<Preparation of Slurry Composition for Negative Electrode>>
100 parts of artificial graphite (volume average particle diameter: 15.6 μm) as the negative electrode active material, and a 2% aqueous solution of carboxymethyl cellulose sodium salt (manufactured by Nippon Paper Industries, product name “MAC350HC”) as a thickening agent at a solid content equivalent. After mixing 1 part and adjusting the solid content concentration to 68% by adding ion-exchanged water, the mixture was mixed at a temperature of 25° C. for 60 minutes to obtain a mixed solution. Ion-exchanged water was further added to the obtained mixed liquid to adjust the solid content concentration to 62%, and then mixed at a temperature of 25° C. for 15 minutes. To the mixed solution, 1.5 parts by weight of an aqueous dispersion containing the styrene-butadiene copolymer as the binder for the negative electrode obtained above in terms of solid content was added, and ion-exchanged water was further added to give a final solid content concentration. Was adjusted to be 52%, and mixing was continued for further 10 minutes to obtain a polymer mixed solution. Then, the polymer mixture was defoamed under reduced pressure to obtain a negative electrode slurry composition.

<<Formation of Negative Electrode Mixture Layer>>
The slurry composition for a negative electrode obtained above was applied on a copper foil (thickness 20 μm) as a current collector using a comma coater so that the film thickness after drying would be about 150 μm. Next, the copper foil coated with the negative electrode slurry composition was conveyed at a rate of 0.5 m/min in an oven at a temperature of 60° C. for 2 minutes to dry the negative electrode slurry composition. .. Then, the copper foil coated with the negative electrode slurry composition was further heat-treated at a temperature of 120° C. for 2 minutes. By performing the same operation on the other surface of the current collector, a negative electrode raw material before pressing, in which the negative electrode mixture layers were formed on both surfaces of the current collector, was obtained. Then, the negative electrode raw material before pressing was rolled by a roll press to obtain a pressed negative electrode in which the thickness of the negative electrode mixture layer on each surface was 80 μm.

<Preparation of electrode (negative electrode) with porous membrane layer>
The slurry composition for a porous film layer obtained above was applied onto the pressed negative electrode obtained above and dried at 50° C. for 3 minutes. The same operation was performed on both surfaces of the negative electrode to obtain a negative electrode with a porous film layer on which one side each had a thickness of 4.0 μm.
Then, the surface roughness Ra of the porous film layer in the obtained negative electrode with the porous film layer was measured. Further, using the obtained negative electrode with a porous film layer and the separator with an adhesive layer obtained above, the adhesiveness between the battery members was evaluated by the method described above. The results are shown in Table 1.

<Production of positive electrode>
<<Preparation of Slurry Composition for Positive Electrode>>
100 parts of LiCoO ₂ (volume average particle diameter: 12.0 μm) as a positive electrode active material, ₂ parts of acetylene black (product of Denki Kagaku Kogyo KK, product name “HS-100”) as a conductive material, and a binder for a positive electrode As a mixture liquid, polyvinylidene fluoride (Kureha Co., Ltd., product name “#7208”) was mixed in an amount of 2 parts in terms of solid content, and N-methylpyrrolidone was added to the mixture as a solvent to adjust the total solid content concentration to 70%. Got And the slurry composition for positive electrodes was obtained by mixing the said mixed liquid with a planetary mixer.

<<Formation of Positive Electrode Material Layer>>
The positive electrode slurry composition obtained above was applied onto an aluminum foil (thickness 20 μm) as a current collector using a comma coater so that the film thickness after drying would be about 150 μm. Next, the aluminum foil coated with the positive electrode slurry composition was transported at a rate of 0.5 m/min in an oven at a temperature of 60° C. for 2 minutes to dry the positive electrode slurry composition. .. Thereafter, the aluminum foil coated with the positive electrode slurry composition was further heat-treated at a temperature of 120° C. for 2 minutes to obtain a positive electrode raw material sheet before pressing. Then, the positive electrode raw material before pressing was rolled by a roll press to obtain a pressed positive electrode.

<Manufacture of secondary battery>
The pressed positive electrode was cut into 49 cm×5.0 cm. On the positive electrode composite material layer of the cut positive electrode, a separator with an adhesive layer cut into 55 cm×5.5 cm was placed. Further, the negative electrode with the porous film layer is cut out into 50 cm×5.2 cm, and the cut out negative electrode with the porous film layer faces the surface of the separator with the adhesive layer that is not in contact with the positive electrode mixture layer and the porous film layer. By arranging in this manner, a laminate having a positive electrode, a separator and a negative electrode was obtained. Here, the adhesive layer is interposed between the positive electrode and the separator, and the porous membrane layer and the adhesive layer are interposed between the negative electrode and the separator in contact with each other. Next, the obtained laminated body was wound with a winding machine to obtain a wound body having a structure of positive electrode/separator with adhesive layer/negative electrode with porous membrane layer. Further, the wound body was pressed at a temperature of 70° C. and a pressure of 1.0 MPa for 8 seconds to form a flat body. Then, the flat body is wrapped with an aluminum packaging material exterior as an exterior of a battery, and an electrolytic solution (electrolyte: LiPF _{6 having} a concentration of 1 M, solvent: ethylene carbonate (EC)/diethyl carbonate (DEC)/vinylene carbonate (VC)= 68.5/30/1.5 (volume ratio) was injected without leaving any air. Furthermore, the opening of the aluminum packaging material was heat-sealed at 150° C. to hermetically close the aluminum outer package, thereby manufacturing a wound type lithium ion secondary battery (I) of 800 mAh.
Then, with respect to the manufactured lithium ion secondary battery, the low temperature output characteristics and the battery state after repeated cycles were evaluated by the above-mentioned method. The results are shown in Table 1.

(Example 2)
In the preparation of the separator with the adhesive layer, the slurry composition for the adhesive layer was applied in the same manner as in Example 1 except that the coating amount of the dried product of the slurry composition for the adhesive layer was 0.05 mg/cm ^2. Similarly, the binder for the porous membrane layer, the slurry composition for the porous membrane layer, the organic particles for the adhesive layer, the binder for the adhesive layer, the slurry composition for the adhesive layer, the separator with the adhesive layer, the porous membrane layer with A negative electrode, a positive electrode, and a secondary battery (I) were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 3)
In the production of the separator with an adhesive layer, the slurry composition for the adhesive layer was applied in the same manner as in Example 1 except that the application amount of the slurry composition for the adhesive layer was 0.5 mg/cm ^2. , Binder for porous membrane layer, slurry composition for porous membrane layer, organic particles for adhesive layer, binder for adhesive layer, slurry composition for adhesive layer, separator with adhesive layer, negative electrode with porous membrane layer, positive electrode , And a secondary battery (I) were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 4)
In the preparation of the organic particles for the adhesive layer, the volume average particle diameter Dp of the organic particles was changed to 0.9 μm by changing the content of sodium dodecylbenzenesulfonate to 0.8 part.
Further, in the production of the electrode with the porous membrane layer, the porous membrane layer was produced in the same manner as in Example 1 except that the pressed positive electrode was used in place of the pressed negative electrode to produce and use the porous membrane layer-containing positive electrode. Binder, porous membrane layer slurry composition, adhesive layer organic particles, adhesive layer binder, adhesive layer slurry composition, adhesive layer separator, porous membrane layer positive electrode, negative electrode, and secondary A battery (I) was manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. At this time, the positive electrode with the porous film layer was used for measuring the surface roughness Ra, and the positive electrode with the porous film layer and the separator with the adhesive layer were used for measuring the adhesiveness between the battery members. The results are shown in Table 1.

(Example 5)
In the preparation of the organic particles for the adhesive layer, the same procedure as in Example 1 was carried out except that the volume average particle diameter Dp of the organic particles was changed to 0.45 μm by changing 1.2 parts of sodium dodecylbenzenesulfonate. The binder for the porous membrane layer, the slurry composition for the porous membrane layer, the organic particles for the adhesive layer, the binder for the adhesive layer, the slurry composition for the adhesive layer, the separator with the adhesive layer, the anode with the porous membrane layer, A positive electrode and a secondary battery (I) were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 6)
In the production of the electrode with the porous film layer, the pressed negative electrode was used as it was without forming the porous film layer, and the surface roughness Ra of the negative electrode mixture layer of the negative electrode was changed to 4.0 μm.
Also, in the preparation of the organic particles for the adhesive layer, the same as Example 1 except that the volume average particle diameter Dp of the organic particles was changed to 4.5 μm by changing the content of sodium dodecylbenzenesulfonate to 0.5 part. Then, organic particles for an adhesive layer, a binder for an adhesive layer, a slurry composition for an adhesive layer, a separator with an adhesive layer, a negative electrode, a positive electrode, and a secondary battery (II) were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. At this time, the pressed negative electrode was used to measure the surface roughness Ra, and the pressed negative electrode and the separator with the adhesive layer were used to measure the adhesiveness between the battery members. The results are shown in Table 1.

(Example 7)
In the production of the electrode with the porous film layer, the surface roughness Ra of the porous film layer was changed to 0.2 μm by setting the drying temperature of the slurry composition for the porous film layer to 80° C.
Further, in the preparation of the organic particles for the adhesive layer, the same as Example 1 except that the volume average particle diameter Dp of the organic particles was 0.3 μm by changing the sodium dodecylbenzenesulfonate to 1.25 parts. Then, the binder for porous membrane layer, the slurry composition for porous membrane layer, the organic particles for adhesive layer, the binder for adhesive layer, the slurry composition for adhesive layer, the separator with adhesive layer, the negative electrode with porous membrane layer , A positive electrode, and a secondary battery (I) were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 8)
In the preparation of the organic particles for the adhesive layer, the same procedure as in Example 1 was carried out except that the glass transition temperature of the organic particles was changed to 30° C. by changing methyl methacrylate to 30 parts and butyl acrylate to 65 parts. Porous membrane layer binder, porous membrane layer slurry composition, adhesive layer organic particles, adhesive layer binder, adhesive layer slurry composition, adhesive layer separator, porous membrane layer negative electrode, positive electrode, And a secondary battery (I) was manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 9)
In the preparation of the organic particles for the adhesive layer, in the same manner as in Example 1 except that the glass transition temperature of the organic particles was changed to 100° C. by changing methyl methacrylate to 95 parts and butyl acrylate to 5 parts, Porous membrane layer binder, porous membrane layer slurry composition, adhesive layer organic particles, adhesive layer binder, adhesive layer slurry composition, adhesive layer separator, porous membrane layer negative electrode, positive electrode, And a secondary battery (I) was manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 10)
In the preparation of the organic particles for the adhesive layer, 0.1 part of t-dodecyl mercaptan was added to change the content of molecules having a weight average molecular weight of 100 or more and 10000 or less in the organic particles to 32% by mass. In the same manner as in Example 1, with a binder for porous membrane layer, slurry composition for porous membrane layer, organic particles for adhesive layer, binder for adhesive layer, slurry composition for adhesive layer, with adhesive layer A separator, a negative electrode with a porous film layer, a positive electrode, and a secondary battery (I) were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
In the production of the separator with the adhesive layer, the binder for the porous membrane layer, the slurry composition for the porous membrane layer, and the porous membrane layer were prepared in the same manner as in Example 1 except that the separator was used as it was without forming the adhesive layer. A negative electrode, a positive electrode, and a secondary battery were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Comparative example 2)
In the preparation of the organic particles for the adhesive layer, the volume average particle diameter Dp of the organic particles was set to 0.1 μm by changing the amount of sodium dodecylbenzenesulfonate to 1.8 parts.
Also, in the production of the separator with an adhesive layer, the same as Example 1 except that the slurry composition for an adhesive layer was applied such that the application amount of the slurry composition for an adhesive layer was 3.0 mg/cm ² , respectively. Then, the binder for porous membrane layer, the slurry composition for porous membrane layer, the organic particles for adhesive layer, the binder for adhesive layer, the slurry composition for adhesive layer, the separator with adhesive layer, the negative electrode with porous membrane layer , A positive electrode, and a secondary battery (I) were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Comparative example 3)
In the preparation of the slurry composition for the porous film layer, titanium oxide (manufactured by Nippon Aerosil Co., Ltd., product name “AEROXIDE (registered trademark) Alu 65”, central particle diameter: 0.04 μm) is used as the non-conductive particles instead of alumina. In the same manner as in Example 1 except that the above was used, the binder for porous membrane layer, the slurry composition for porous membrane layer, the organic particles for adhesive layer, the binder for adhesive layer, and the slurry composition for adhesive layer. , A separator with an adhesive layer, a negative electrode with a porous film layer, a positive electrode, and a secondary battery (I) were produced.
Then, measurement and evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

From Table 1, in the non-aqueous secondary battery of Comparative Example 1 including the separator having no adhesive layer containing organic particles, as compared with Examples 1 to 10 having the adhesive layer, adhesiveness between battery members and repeated cycles It can be seen that the swelling of the battery afterward is significantly deteriorated. Further, it can be seen that the low temperature output characteristics of the secondary battery are deteriorated.
Further, in the non-aqueous secondary battery of Comparative Example 2 including the separator having the adhesive layer containing the organic particles having the volume average particle diameter Dp of less than 0.2 μm, the organic particles having Dp of 0.2 μm or more and 5.0 μm or less are used. It can be seen that the low-temperature output characteristics of the secondary battery are significantly deteriorated as compared with Examples 1 to 10 used. Also, it can be seen that the adhesion between the battery members and the bulge of the battery after repeated cycles are worse.
Further, in Comparative Example 3 using a negative electrode having a porous membrane layer having a surface roughness Ra of less than 0.1 μm, Example 1 using an electrode having a porous membrane layer having Ra of 0.1 μm or more and 5.0 μm or less. As compared with Nos. 10 to 10, it can be seen that the adhesion between the battery members, the low-temperature output characteristics of the secondary battery, and the bulge of the battery after repeated cycles are all significantly deteriorated.

According to the present invention, high adhesion between battery members such as electrodes and separators, good output characteristics, and a non-aqueous secondary battery capable of arranging excellent battery performance such as good battery state after repeated cycles, and A method for manufacturing the non-aqueous secondary battery can be provided.

Claims (7)

Provided with a positive electrode, a negative electrode, a separator, and an electrolytic solution,
The separator has an adhesive layer containing organic particles,
At least one of the positive electrode and the negative electrode has a porous film layer in contact with the adhesive layer,
The surface roughness Ra of the porous membrane layer is 0.1 μm or more and 5.0 μm or less,
The volume average particle diameter Dp of the organic particles Ri der than 5.0μm or less 0.2 [mu] m,
Satisfying the relation of Dp-Ra>0,
Non-aqueous secondary battery. Provided with a positive electrode, a negative electrode, a separator, and an electrolytic solution,
The separator has an adhesive layer containing organic particles,
The surface roughness Ra of the surface of at least one of the positive electrode and the negative electrode that is in contact with the adhesive layer is 0.1 μm or more and 5.0 μm or less,
The volume average particle diameter Dp of the organic particles Ri der than 5.0μm or less 0.2 [mu] m,
Satisfying the relation of Dp-Ra>0,
Non-aqueous secondary battery. The non-aqueous secondary battery according to claim 1, wherein the porous membrane layer contains non-conductive particles. The non-aqueous secondary battery according to claim 1, wherein the glass transition temperature of the organic particles is 10° C. or higher and 110° C. or lower. The non-aqueous secondary battery according to any one of claims 1 to 4, wherein the organic particles have a content of molecules having a weight average molecular weight of 100 or more and 10,000 or less and 1 mass% or more and 40 mass% or less. The non-aqueous secondary battery according to claim 1, which is a wound type or a laminated type. It is a manufacturing method of the non-aqueous secondary battery according to any one of claims 1 to 6,
The adhesive layer is formed using a slurry composition for an adhesive layer containing the organic particles,
The coating amount of the dried product of the slurry composition for the adhesive layer is 0.05 mg/cm ² or more and 3.0 mg or more.
/Cm ² or less,
Manufacturing method of non-aqueous secondary battery.