JP3471238B2 - Manufacturing method of non-aqueous electrolyte secondary battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] The present invention relates to a non-aqueous electrolyte secondary battery.
The present invention relates to a method for manufacturing a pond and a nonaqueous electrolyte secondary battery. [0002] 2. Description of the Related Art Currently, non-mobile devices such as mobile phones are
Thin lithium ion secondary battery as water electrolyte secondary battery
Has been commercialized. This battery has a lithium cover
Oxide (LiCoO₂), Graphite material and carbon
Material, organic solvent in which lithium salt is dissolved in electrolyte,
A porous membrane is used for the radiator. [0003] As portable equipment becomes thinner, the thickness of batteries becomes thinner.
Although it is requested that the thickness be 4 mm or less,
It is difficult to commercialize a thin lithium ion secondary battery. This
For this reason, card-type refills using a conventional polymer electrolyte
A rechargeable lithium battery has been proposed and is being developed for practical use.
You. [0004] However, the use of polymer electrolyte
Non-aqueous electrolyte was retained in polymer
Lithium using a non-aqueous electrolyte because it is a gel polymer
The impedance at the electrode interface is higher than that of the secondary battery.
And low lithium ion conductivity.
You. Also, increase the thickness to increase lithium ion mobility.
When the thickness is reduced, the amount of active material of the positive and negative electrodes decreases,
Energy density is reduced. Accordingly, lithium using a polymer electrolyte
Secondary batteries are impregnated with a non-aqueous electrolyte in a solution / liquid state.
Volume energy density compared to thin lithium secondary batteries
Problems such as poor temperature and large current characteristics and low temperature characteristics
is there. [0006] SUMMARY OF THE INVENTION The object of the present invention is to
Capacity, high current characteristics, low temperature characteristics and cycle performance
Non-aqueous electrolyte secondary battery that can be
It is intended to provide a method for producing the same. Non-electrode group
Non-aqueous electrolysis in which water electrolyte is impregnated in a solution / liquid state
It is possible to reduce the thickness of the liquid secondary battery,
Capacity, high current characteristics and cycle performance have been improved
It is an object of the present invention to provide a lysate secondary battery. [0007] Means for Solving the Problems The present invention provides:Positive and negative electrodes
A separator with at least one end extending from the positive and negative electrodes
A process of preparing an electrode group with a
Before the solution in which 0.1 to 2.5% by weight of the
Impregnating the electrode group and vacuum drying the electrode group.
Between the positive electrode and the separator and between the negative electrode and the separator
Forming a porous adhesive layer on the electrode group;
Impregnating with a water electrolyte.
This is a method for manufacturing a non-aqueous electrolyte secondary battery. [0008] [0009] BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a non-aqueous electrolyte according to the present invention
Diagram of a secondary battery (eg, a thin lithium-ion secondary battery)
This will be described in detail with reference to FIGS. FIG. 1 illustrates the present invention.
Related non-aqueous electrolyte secondary batteries (eg, thin lithium ion
FIG. 2 is an enlarged cross-sectional view showing part A of FIG.
It is a large map. [0010] As shown in FIG.
The exterior material 1 made of lum surrounds the electrode group 2. Electric
The electrode group 2 includes, for example, a current collector 3 made of a porous conductive substrate.
A positive electrode 5 having a structure in which the positive electrode layer 4 is supported;
A negative electrode layer 7 is provided on a current collector 6 made of a porous conductive substrate.
Negative electrode 8 having a supported structure, positive electrode layer 4 and negative electrode layer
7 and the porous adhesive layers 9a and 9b
Separate having porous adhesive layers 9a and 9b adhered to its surface
Data 10. The non-aqueous electrolytic solution is contained in the exterior material 1.
You. One end of the strip-shaped positive electrode lead 11 has a positive electrode collection of the electrode group 2.
Connected to the electric body 5 and the other end is extended from the exterior material 1
I have. On the other hand, one end of the strip-shaped negative electrode lead 12 is
Negative electrode current collector 7 and the other end extends from the exterior material 1.
Has been issued. At least one end of the separator 10 has a positive electrode and a positive electrode.
And extend from the negative electrode. As a result, external impact
Short circuit does not easily occur even when
Excellent in integrity. Also adheres to the extended separator
It is desirable to hold the agent. It was extended
The strength of the separator is stronger, especially for batteries
Short-circuiting when a shock is applied. Sa
In addition, when the battery is under high temperature
The shrinkage of the parator is suppressed, preventing a short circuit between the positive and negative electrodes.
Safety can be ensured. Then the adhesive
More preferably, it is porous. Next, a positive electrode 5, a negative electrode 8, a separator 10,
The adhesive layers 9a and 9b and the non-aqueous electrolyte will be described in detail.
You. 1) Positive electrode The positive electrode 5 is such that the positive electrode layer 4 containing the active material is formed on one side of the current collector 3.
Or it has a structure carried on both sides. The positive electrode layer comprises a positive electrode active material, a conductive agent,
A binder for binding the positive electrode active material particles may be included.
The positive electrode 5 is formed, for example, by applying a conductive agent and a binder to the positive electrode active material.
Suspend in the appropriate solvent, apply this suspension to the current collector, dry and
It is manufactured by making it thin plate. As the positive electrode active material, various oxides, for example,
Manganese dioxide, lithium manganese composite oxide, lithium
-Containing nickel oxide, lithium-containing cobalt compound
Material, lithium-containing nickel-cobalt oxide, lithium-containing
Iron oxide, vanadium oxide containing lithium, disulfide
Chalcogen compounds such as titanium iodide and molybdenum disulfide
And so on. Among them, lithium-containing Kobal
Oxide (eg, LiCoO)₂ ), Lithium containing
Nickel cobalt oxide (eg, LiNi_0.8Co
_0.2O₂ ), Lithium manganese composite oxide (for example,
For example, LiMn₂O₄ , LiMnO₂ ), High
It is preferable because a voltage can be obtained. As the conductive agent, for example, acetylene black is used.
, Carbon black, graphite and the like. As the binder, for example, polytetrafluoro
Polyethylene (PTFE), polyvinylidene fluoride (PV
dF), ethylene-propylene-diene copolymer (EP
DM), using styrene-butadiene rubber (SBR), etc.
Can be Composition ratio of positive electrode active material, conductive agent and binder
80 to 95% by weight of the positive electrode active material and 3 to 20
%, Binder 2 to 7% by weight
No. As the current collector, a conductive substrate having a porous structure or
Alternatively, a non-porous conductive substrate can be used. These guides
The conductive substrate is, for example, aluminum, stainless steel, or
Can be formed from nickel. Among them, a hole having a diameter of 3 mm or less is 10 cm.²
Two-dimensional porous structure existing at a rate of one or more
It is preferable to use a conductive substrate having a structure. Sand
That is, the diameter of the hole opened in the conductive substrate is larger than 3 mm.
If it becomes too strong, sufficient positive electrode strength may not be obtained.
You. On the other hand, the proportion of holes having a diameter of 3 mm or less is smaller than the range.
When the amount is low, the non-aqueous electrolyte is evenly penetrated into the electrode group
And it is difficult to obtain a sufficient cycle life.
There is a risk of becoming. Hole diameter is in the range of 0.1-1mm
Is more preferable. In addition, the existence ratio of holes is 1
0cm² It is better to make it in the range of 10 to 20 pieces per
preferable. The aforementioned hole having a diameter of 3 mm or less has a size of 10 cm.²
Two-dimensional porous structure existing at a rate of one or more
The conductive substrate having the structure has a thickness of 15 to 100 μm.
Preferably, it is enclosed. Reduce thickness to less than 15μm
In such a case, sufficient positive electrode strength may not be obtained. one
On the other hand, if the thickness exceeds 100 μm, the battery weight and electrode
The group thickness increases, the weight energy density of thin secondary batteries
And it is difficult to make the volume energy density high enough
There is a risk of becoming. A more preferable range of the thickness is 30 to 8
0 μm. 2) Negative electrode 8 In the negative electrode, the negative electrode layer 7 is supported on one or both sides of the current collector 6
It has the structure which was done. The negative electrode 8 contains a negative electrode material and a binder.
You may go out. For example, lithium ion
A carbonaceous material that absorbs and releases oxygen and a binder in the presence of a solvent
And the resulting suspension was applied to a current collector and dried.
Then press once or 2-5 times at desired pressure
Can be manufactured by pressing As the carbonaceous material, graphite, coke, carbon
Graphite or carbonaceous materials such as fibers and spherical carbon,
Thermosetting resin, isotropic pitch, mesophase pitch,
Sophase pitch-based carbon fiber, mesophase spheres, etc.
(Especially, mesophase pitch-based carbon fibers are preferred)
Obtained by performing heat treatment at 500-3000 ° C
Graphite materials or carbonaceous materials can be used.
Above all, by setting the temperature of the heat treatment to 2000 ° C or higher.
And the spacing d of the (002) plane₀₀₂ Is 0.34
Use a graphitic material having graphite crystals of 0 nm or less
Is preferred. Such a graphitic material as a carbonaceous material
Non-aqueous electrolyte secondary batteries with negative electrodes
And large current characteristics can be greatly improved. Surface distance d
₀₀₂Is more preferably 0.336 nm or less.
No. As the binder, for example, polytetrafluoro
Polyethylene (PTFE), polyvinylidene fluoride (PV
dF), ethylene-propylene-diene copolymer (EP
DM), styrene-butadiene rubber (SBR), carbo
Xymethylcellulose (CMC) can be used
You. The mixing ratio of the carbonaceous material and the binder is
90 to 98% by weight of the binder and 2 to 20% by weight of the binder.
Preferably. In particular, the carbonaceous material was in the form of a negative electrode.
5 to 20 g / m in the state²It is preferable to be within the range. As the current collector, a conductive substrate having a porous structure is used.
Alternatively, a non-porous conductive substrate can be used.
These conductive substrates are, for example, copper, stainless steel, or
It can be formed from nickel. Among them, a hole having a diameter of 3 mm or less is 10 cm.²
Two-dimensional porous structure existing at a rate of one or more
It is preferable to use a conductive substrate having a structure. Sand
That is, the diameter of the hole of the conductive substrate is larger than 3 mm.
In such a case, sufficient negative electrode strength may not be obtained. one
On the other hand, the proportion of holes with a diameter of 3 mm or less is less than the range
When this happens, the non-aqueous electrolyte can be evenly penetrated into the electrode group.
It will be difficult to obtain sufficient cycle life
There is fear. Hole diameter should be in the range of 0.1-1mm
Is more preferable. In addition, the existence ratio of holes is 10 cm
² More preferably in the range of 10-20 per
No. The aforementioned hole having a diameter of 3 mm or less is 10 cm.²
Two-dimensional porous structure existing at a rate of one or more
The conductive substrate having the structure has a thickness of 10 to 50 μm.
Is preferable. If the thickness is less than 10 μm,
There is a possibility that sufficient negative electrode strength cannot be obtained. Meanwhile, thick
Exceeds 50 μm, the battery weight and the thickness of the electrode group
Increases the weight energy density and volume of thin secondary batteries.
May be difficult to increase energy density sufficiently
There is. As the negative electrode material, the above-described lithium ion
In addition to carbonaceous materials that occlude and release metals, metal oxides or gold
Containing genus sulfide or metal nitride, or lithium
Metal or lithium alloy
it can. As the metal oxide, for example, tin oxide
Material, silicon oxide, lithium titanium oxide, niobium oxide
And tungsten oxide. As the metal sulfide, for example, tin sulfide
And titanium sulfide. Examples of the metal nitride include lithium core
Baltic nitride, lithium iron nitride, lithium manganese nitride
And the like. As the lithium alloy, for example, lithium
Aluminum alloy, lithium tin alloy, lithium lead alloy
Gold, lithium silicon alloy and the like can be mentioned. 3) Separator 10 Examples of separators include polyethylene and polypropylene.
Contains pyrene or polyvinylidene fluoride (PVdF)
It is possible to use a porous film, a nonwoven fabric made of synthetic resin, etc.
Wear. Among them, polyethylene or polypropylene
Or a porous film consisting of both
This is preferable because safety can be improved. The thickness of the separator should be 30 μm or less.
Is preferred. If the thickness exceeds 30μm, between the positive and negative electrodes
Distance may increase and the internal resistance may increase.
You. The lower limit of the thickness is preferably 5 μm.
No. When the thickness is less than 5 μm, the strength of the separator is remarkable.
Internal short circuit is likely to occur.
You. The upper limit of the thickness is more preferably 25 μm.
And the lower limit is more preferably 10 μm.
No. The separator was kept at 120 ° C. for one hour.
The heat shrinkage when present is preferably 20% or less.
New If the heat shrinkage exceeds 20%, the positive and negative electrodes and separator
It becomes difficult to make the adhesive strength of the radiator sufficient
There is fear. The heat shrinkage should be less than 15%
preferable. The separator has a porosity of 30 to 60%.
It is preferred that it is an enclosure. This is for the following reasons
Things. When the porosity is less than 30%, the separator
May be difficult to obtain high electrolyte retention
There is. On the other hand, if the porosity exceeds 60%, sufficient separation
There is a possibility that the radiator strength cannot be obtained. Porosity more
The preferred range is 35-50%. The separator has an air permeability of 600 seconds / 1.
00cm³ The following is preferred. Air permeability
600 seconds / 100cm³ Exceeds, the separator
And it is difficult to obtain high lithium ion mobility
There is fear. The lower limit of the air permeability is 100 seconds /
100cm³ Is preferable. 1 air permeability
00 seconds / 100cm³ If less, enough separation
This is because there is a possibility that the data strength cannot be obtained. Air permeability
The upper limit of the excess rate is 500 seconds / 100cm³ To do
More preferably, the lower limit is 150 seconds / 100 cm³
Is more preferable. In the present invention, the number of separators 10 is small.
One end of which extends from the positive and negative electrodes
are doing. The extended separator is 0.1 mm from the negative electrode end.
It is desirable that the extension is 25 mm or more. Too little
Internal short circuits are likely to occur. Also, the extension of the separator
It is desirable that a porous adhesive layer also exists in the
New Separator extends inside all sides
It is desirable to prevent short circuit. 4) Porous adhesive layers 9a, 9b The porous adhesive layers 9a and 9b are dissolved in a non-aqueous electrolyte.
And maintain high adhesiveness while holding non-aqueous electrolyte
It is desirable to be formed from a polymer material that can be used.
Furthermore, such polymer materials have high lithium ion conductivity
And still more preferred. The specific polymer material is polyacrylonitrile
Toril (PAN), Polyacrylate (PMMA), PO
Polyvinylidene fluoride (PVdF), polyvinyl chloride (P
VC) or polyethylene oxide (PEO)
Can be mentioned. In particular, polyvinylidene fluoride (P
VdF) is preferred. Polyvinylidene fluoride (PVd
F) can hold a non-aqueous electrolytic solution,
Incorporation of manganese causes some gelation, which results in ionic conduction in the positive electrode.
Properties can be further improved. 5) Non-aqueous electrolyte The non-aqueous electrolyte is prepared by dissolving the electrolyte in a non-aqueous solvent.
It is a liquid electrolyte prepared. As the non-aqueous solvent, a solvent for a lithium secondary battery may be used.
A known non-aqueous solvent can be used as the medium, and is particularly limited.
Propylene carbonate (PC) and ethylene
Lower viscosity than lencarbonate (EC) and PC or EC
At least one non-aqueous solvent having a donor number of 18 or less
(Hereinafter referred to as a second solvent) and a non-aqueous solvent mainly comprising a mixed solvent.
It is preferable to use a solvent. As the second solvent, for example, chain carbon is used.
Preferred is dimethyl carbonate (DMC),
Chill ethyl carbonate (MEC), diethyl carbonate
(DEC), ethyl propionate, propionate
Chill, γ-butyrolactone (γ-BL), acetonitrile
(AN), ethyl acetate (EA), toluene, xylene
Alternatively, methyl acetate (MA) and the like can be mentioned. these
Is used alone or in the form of a mixture of two or more.
Can be. In particular, the second solvent has a donor number of 16.
More preferably, it is 5 or less. The viscosity of the second solvent is 28 m at 25 ° C.
It is preferably at most p. Ethylene in mixed solvent
-The amount of carbonate or propylene carbonate,
The volume ratio is preferably 10 to 80%. Better
Ethylene carbonate or propylene carbonate
The amount of the mixture is 20 to 75% by volume. The more preferable composition of the mixed solvent is EC and M
EC, EC and PC and MEC, EC and MEC and DEC, E
C and MEC and DMC, EC and MEC and PC and DEC
In a mixed solvent, the volume ratio of MEC should be 30-80%
Is preferred. A more preferred volume ratio of MEC is 40 to
It is in the range of 70%. Examples of the electrolyte contained in the non-aqueous electrolyte include:
For example, lithium perchlorate (LiClO ₄), Phosphorus hexafluoride
Lithium oxide (LiPF₆), Lithium borofluoride (Li
BF ₄), Lithium arsenic hexafluoride (LiAsF)₆), To
Lithium trifluorometasulfonate (LiCF₃S
O₃), Bistrifluoromethylsulfonyl imidolithic
[LiN (CF₃SO₂)₂] And other lithium salts
(Electrolyte). Among them, LiPF₆, LiBF
₄It is preferable to use The amount of the electrolyte dissolved in the non-aqueous solvent is 0.1.
It is desirable to set it as 5 to 2.0 mol / 1. The amount of the non-aqueous electrolyte is 100 m
It is preferable to set the amount to 0.2 to 0.6 g per Ah. This
This is for the following reasons. Non-aqueous electrolyte volume
If it is less than 0.2 g / 100 mAh, the positive electrode and negative electrode
It may not be possible to maintain sufficient on-conductivity.
You. On the other hand, the amount of the non-aqueous electrolyte exceeds 0.6 g / 100 mAh.
The amount of electrolyte becomes large,
Sealing may be difficult. More non-aqueous electrolyte volume
A preferable range is 0.4 to 0.55 g / 100 mAh.
You. 6) Exterior material 1 The exterior material 1 is made of, for example, flexible synthetic resin or gold.
A thin film of a genus can be used. Especially non-aqueous electrolyte
In the case of a system battery, aluminum or the like is
Laminated film (multilayer film) with barrier layer inserted is preferred
No. The inclusion of an aluminum layer, especially for non-aqueous electrolytes
In the case of batteries, water can be prevented from
This is preferable because the life of the pond can be extended. The thickness of the exterior material is in the range of 50 to 300 μm
It is preferable that It is easy to deform and break if it is too thin
If it is too thick, the effect of thinning will be reduced. The non-aqueous electrolyte secondary battery according to the present invention (for example,
Thin lithium ion having the structure shown in FIGS.
The following two types of manufacturing methods are used to manufacture secondary batteries.
Fabrication method. However, the non-aqueous electrolyte solution 2 according to the present invention
The manufacturing method of the secondary battery is as follows if it is within the scope of the present invention.
It is not limited to the following form. <First Manufacturing Method> (First step) First, a separator is provided between the positive electrode and the negative electrode.
To form an electrode group with a porous sheet interposed therebetween. The positive electrode is formed, for example, by adding a conductive agent to a positive electrode active material.
And the binder are suspended in a suitable solvent, and the suspension is collected.
It is made by applying it to the body and drying it to make it a thin plate.
You. As the positive electrode active material, conductive agent, binder and current collector
Are the same as those described in the section of (1) Positive electrode described above.
Can be mentioned. The negative electrode absorbs, for example, lithium ions.
The negative electrode material such as carbonaceous material to be stored and released and the binder are
Kneaded in the presence, apply the resulting suspension to the current collector, dry
After drying, press once or press 2-5 times at the desired pressure.
It is produced by step pressing. As the above-mentioned carbonaceous material, binder and current collector
Are the same as those described in the section of (2) Negative electrode described above.
Can be mentioned. As the porous sheet of the separator,
The same as described in the above (3) Separator column
Can be used. (Second step) The electrode group is placed in an exterior material processed into a bag shape.
The laminating surface is stored from the opening. Dissolve the adhesive in the solvent
The solution obtained by that from the opening in the exterior material
The solution is injected into an electrode group, and the solution is impregnated into the electrode group. As the exterior material, the aforementioned (7) exterior
You can list the same ones as explained in the material section.
You. As the adhesive, the aforementioned (4) porous
Similar to the polymer materials described in the column of quality adhesive layer
I can do it. In particular, polyvinylidene fluoride (PV
dF) is preferred. The solvent includes an organic solvent having a boiling point of 200 ° C. or less.
It is desirable to use a solvent. As such an organic solvent
Is, for example, dimethylformamide (boiling point 153 ° C.)
Can be mentioned. Organic solvent boiling point exceeds 200 ℃
Then, the temperature of vacuum drying described below was set to 100 ° C. or less.
In such a case, the drying time may take a long time. In addition, organic solvents
Is preferably set to 50 ° C. Organic
When the boiling point of the solvent is lower than 50 ° C., the solution is
There is a risk that the organic solvent will evaporate during injection.
is there. The upper limit of the boiling point is more preferably set to 180 ° C.
More preferably, the lower limit of the boiling point should be 100 ° C.
More preferred. The concentration of the adhesive in the solution is 0.05 to
It is preferred to be in the range of 2.5% by weight. This is
This is for such a reason. The concentration is 0.05 weight
%, The positive and negative electrodes and separator have sufficient strength.
Adhesion may be difficult. Meanwhile, the concentration
Exceeds 2.5% by weight, the non-aqueous electrolyte can be retained.
It is difficult to obtain sufficient porosity of the electrode
The impedance may be significantly increased. Interface
When the impedance increases, the capacity and large current discharge characteristics
It drops significantly. A more preferable range of the concentration is 0.1 to
1.5% by weight. The injection amount of the solution depends on the adhesive of the solution.
When the concentration is 0.1 to 2.5% by weight, the battery capacity is 10
It is preferable to be in the range of 0.1 to 2 ml per 0 mAh.
New This is due to the following reasons. Note
If the amount is less than 0.1 ml, the positive electrode, the negative electrode and the separator
May not be able to sufficiently increase the
You. On the other hand, when the injection amount exceeds 2 ml, the
This causes a decrease in lithium ion conductivity and an increase in internal resistance.
Discharge capacity, large current discharge characteristics and charge / discharge
There is a possibility that it may be difficult to improve the hull characteristics. Said
A more preferable range of the injection amount is about 100 mAh of battery capacity.
It is 0.15 to 1 ml. (Third step) The electrode group is dried by vacuum drying.
The solvent in the solution is evaporated, and the positive electrode, the negative electrode and the separator are removed.
A porous adhesive layer can be formed between the heaters. Also, the positive electrode,
Adhesive in the fine gap between negative electrode and separator
Make the polymer exist. Also, on the extension of the separator
Can also form a porous adhesive layer. Also this vacuum
Simultaneous removal of water contained in the electrode group by drying
It can be carried out. It should be noted that the porous adhesive layer has a small amount of solvent.
Medium is allowed. The vacuum drying is performed at 100 ° C. or less.
Is preferred. This is due to the following reasons.
When the vacuum drying temperature exceeds 100 ° C., the separator
May significantly shrink. Heat shrinkage increases
The positive electrode, negative electrode and separator
It becomes difficult to adhere firmly. In addition, the heat
Shrink, porous containing polyethylene or polypropylene
Remarkably occurs when a high-quality film is used as a separator.
Cheap. The lower the temperature of vacuum drying, the higher the heat of the separator
Shrinkage can be suppressed, but vacuum drying temperature is less than 40 ° C
In this case, it may be difficult to evaporate the solvent sufficiently.
There is. For this reason, the vacuum drying temperature is 40 to 100 ° C.
Is more preferable. (Fourth step) Non-aqueous electrolyte is injected into the electrode group in the exterior material
After that, the opening of the exterior material is sealed to reduce the thickness.
Assemble the non-aqueous electrolyte secondary battery. As the non-aqueous electrolyte, the aforementioned (5)
Use the same one as explained in the section on non-aqueous electrolyte.
Can be. In the manufacturing method described above, the adhesive is melted.
The solution is injected after the electrode group is stored in the exterior material.
However, the injection may be performed without storing in the exterior material. this
First, place a separator between the positive and negative electrodes
An electrode group is prepared. The electrode group was impregnated with the solution
Thereafter, the electrode group is subjected to vacuum drying to
Evaporate the solvent, between the positive electrode, negative electrode and separator
Allow a porous adhesive layer to be present. Such an electrode group
After storing it in the exterior material, inject a non-aqueous electrolyte and seal it.
Manufacturing a thin non-aqueous electrolyte secondary battery
Can be. An adhesive may be applied to the outer periphery of the electrode group before storage.
No. As a result, adhesion is made between the electrode group and the exterior material.
You. <Second manufacturing method> (First step) First, a positive electrode, a negative electrode and a separator are prepared.
You. For the positive electrode, negative electrode, and separator,
It can be obtained in the same manner as in the first step. (Second step) Obtained by dissolving the adhesive in a solvent
The solution is applied to the surface of the positive electrode layer of the positive electrode and the surface of the negative electrode layer of the negative electrode.
You. Separator between the positive and negative electrode layers coated with the solution
Place and make a laminate. The adhesive and the solvent are used in the second method of the first manufacturing method.
The same one as described in the step section may be used. The concentration of the adhesive in the solution is 0.1 to 5
It is preferred to be in the range of weight%. This is like
It is for a reason. Said concentration to less than 0.1% by weight
Then, the positive and negative electrodes and the separator are bonded with sufficient strength
Can be difficult. On the other hand, when the concentration is 5 wt.
%, The amount is large enough to hold the non-aqueous electrolyte.
It is difficult to obtain the porosity, and the interface impedance of the electrode
May be significantly increased. Interface impedance
Increases, capacity and large current discharge characteristics decrease significantly.
You. A more preferred range of the concentration is 0.2 to 2% by weight.
You. (Third step) In the laminate under normal pressure or reduced pressure,
The solvent contained in the solution is dried by vacuum drying.
Form a porous adhesive layer between the positive and negative electrode layers and the separator
Then, an electrode group is obtained, and the electrode group is processed into a bag-like exterior material.
To be stored. The electrode group was housed in the exterior material first
Thereafter, vacuum drying may be performed. Before storing, touch the outer periphery of the electrode group.
An adhesive may be applied. As a result, the electrode group
Adhesion is made between them. As the exterior material, the above (6)
You can list the same ones as described in
You. The condition of vacuum drying is the third process of the first manufacturing method.
The conditions described in the above column may be used. (Fourth step) Non-aqueous electrolyte was injected into the electrode group in the exterior material
After that, the non-aqueous electrolytic thin
A liquid secondary battery is manufactured. As the non-aqueous electrolyte, the aforementioned (5) non-aqueous
It is possible to use the same ones as explained in the column of electrolyte.
it can. In the present invention, the first manufacturing method
According to the report, porous adhesive is also applied to the extension of the separator.
It is more preferable because the layer can be easily formed. [0073] BRIEF DESCRIPTION OF THE DRAWINGS FIG.
And will be described in detail. Embodiment 1 <Preparation of Positive Electrode> First, lithium cobalt oxide (Li_x
CoO₂X is 0 ≦ X ≦ 1) powder 91 weight
% Acetylene black 3.5% by weight, graphite
3.5% by weight and ethylene propylene diene monomer powder
2% by weight and toluene are added and mixed together to a thickness of 15μ.
m on the both sides of a current collector made of aluminum foil
Then, by pressing, the electrode density becomes 3 g / cm.³so,
A positive electrode having a structure in which a positive electrode layer is supported on both surfaces of a current collector is manufactured.
Was. The size of the positive electrode was 45 mm long and 75 mm wide.
Was. <Production of negative electrode> Heat treatment at 3000 ° C. as carbonaceous material
Mesophase pitch-based carbon fiber (fiber diameter 8 μm, flat
The average fiber length is 20 μm, and the average face spacing (d₀₀₂) Is 0.3
93% by weight of a 360 nm powder and polyf
7% by weight of vinylidene difluoride (PVdF)
Is applied to one side of a current collector made of a copper foil having a thickness of 15 μm,
After drying and pressing, the electrode density is 1.3 g / c.
m³The negative electrode has a structure in which the negative electrode layer is supported on one side of the current collector.
Was prepared. The size of the negative electrode is 46 mm long and 76 m wide
m. <Separator> The thickness is 25 μm, at 120 ° C. for 1 hour.
Made of polyethylene with 20% heat shrinkage and 50% porosity
A separator made of a porous film was prepared. Separe
The size of the data was 48 mm in length and 78 mm in width. This
The size of the four sides when stacked on the positive and negative electrodes
Is the length extending from the positive electrode and the negative electrode.
1.5mm width each, 1mm width from the negative electrode
It is the size that protrudes. <Preparation of electrode group> Polyacrylonitrile as adhesive
(PAN) in dimethylformamide (boiling point 153)
C) 1% by weight was dissolved in the solution. The resulting solution is
This coating is applied to the surface of the positive electrode layer and the surface of the negative electrode layer of the negative electrode.
A separator was arranged between the surface and the surface of the negative electrode layer. Separe
The four sides of the data are 1.5 mm wide from the edge of the positive electrode,
From each other with a width of 1 mm. In addition,
Before lamination, a strip-shaped positive electrode lead is welded to the positive electrode
A strip-shaped negative electrode lead was welded to the current collector of the pole. The product obtained
Vacuum dry the layer at 80 ° C for 12 hours
Each electrode layer and separator by evaporating muamide
A porous adhesive layer was formed between them to obtain an electrode group. <Preparation of non-aqueous electrolyte> Lithium hexafluorophosphate (LiP
F₆) With ethylene carbonate (EC) and methyl ethyl
Mixed solvent of carbonate (MEC) (mixed volume ratio 1:
A non-aqueous electrolyte was prepared by dissolving 1.4 mol / 1 in 2). The electrode group and the non-aqueous electrolyte were applied to both sides of the aluminum foil.
100μm thick laminated foil covered with polypropylene
The film was formed into a bag shape, and the electrode group was housed in the bag. Non-aqueous electrolysis is applied to the electrodes in the laminate film.
The solution was adjusted so that the amount per 1 Ah of battery capacity was 5.0 g.
Inject and seal to have the structure shown in FIGS.
0.5mm in height, 54mm in height, 86mm in width
A water electrolyte secondary battery was assembled. Embodiments 2 to 5 Except that the adhesive is a polymer of the type shown in Table 1 below,
A thin non-aqueous electrolyte secondary battery having the same configuration as in the first embodiment described above.
Assembled the pond. Embodiment 6 Using a negative electrode made of an aluminum plate with a thickness of 0.1 mm
Thin non-aqueous electrolysis having the same configuration as in the first embodiment except that
A liquid secondary battery was assembled. Embodiment 7 Vacuum drying at 100 ° C for 12 hours when preparing the electrode group
Other than the above, a thin non-aqueous electrolyte was prepared in the same manner as in Example 1 described above.
The secondary battery was assembled. Embodiment 8 Vacuum drying at 140 ° C for 12 hours when preparing the electrode group
Other than the above, a thin non-aqueous electrolyte was prepared in the same manner as in Example 1 described above.
The secondary battery was assembled. Embodiment 9 The positive and negative electrodes manufactured in the same manner as described in Example 1
Separate the electrode and separator between the positive and negative electrode layer surfaces.
The stackers were arranged in such a way that the radiators were arranged. Four sides of the separator are positive
1.5 mm width from each end of the pole, 1 mm each from the negative electrode
It protruded in the width of mm. Before lamination, the positive electrode
Weld a strip-shaped positive electrode lead to the current collector, and
The negative electrode lead was welded. Laminate film bag
The lamination surface described above with the electrode group on the one molded into
It was stored so that it could be seen from. Polyfluoride as adhesive
Nylidene (PVdF) is converted to dimethyl phor
0.3% by weight dissolved in muamide (boiling point: 153 ° C)
Was. The obtained solution is applied to the electrodes in the laminate film.
The amount per 100 mAh of pond capacity is the same as in Example 1.
Into the electrode group, and
Attached to the entire surface of the pole group. Next, the electrode group in the laminate film was
The organic solvent is removed by performing vacuum drying at 40 ° C. for 24 hours.
Evaporate the electrode group into the gap between the positive electrode, the negative electrode and the separator.
A porous bonded portion was formed on the surface. In addition, the separator
Adhesive is also held on the parts protruding from the positive and negative electrodes
I was able to. Non-aqueous electrolysis is applied to the electrodes in the laminate film.
The amount of liquid per 1 Ah of battery capacity is the same as in Example 1.
And has the structure shown in FIGS.
0.5mm thick, 54mm long, 86mm wide
A non-aqueous electrolyte secondary battery was assembled. Comparative Example 1 The same positive electrode layer of the positive electrode as described in Example 1 and Example 1
Example 1 between the negative electrode layer of the negative electrode similar to that described in
By arranging the same separator as explained in
An electrode group was prepared. As described in the electrode group and the first embodiment
A similar non-aqueous electrolyte is stored in a laminate film and
The amount of non-aqueous electrolyte per 1 Ah of pond capacity is 5.0 g and the thickness is
0.5mm, height 54mm, width 86mm thin non-aqueous
A liquid dissolving secondary battery was assembled. Comparative Example 2 LiPF to polyacrylonitrile₆, EC and PC
The gel electrolyte obtained by adding and mixing
60μm, 65% porosity nonwoven fabric separation
Impregnated. Such a separator is described in Example 1.
It should be placed between the negative electrode layer and the negative electrode
An electrode group was prepared. As described in the electrode group and Example 1.
Non-aqueous electrolyte similar to the above is stored in the laminated film
And has the structure shown in FIG.
Of non-aqueous electrolyte is 0 g (with non-aqueous electrolyte held in PAN)
0.5mm thick, 54mm wide, and height
Was assembled to form a non-aqueous electrolyte secondary battery having a thickness of 8 mm. Comparative Example 3 Example except that the end of the separator is the same as the end of the negative electrode
A thin non-aqueous electrolyte secondary battery similar to that of No. 1 was assembled. Examples 1 to 5, 7 to 9 and Comparative Examples
For the secondary batteries of 1 to 3, 4.2 at a charging current of 40 mA.
After charging to V for 5 hours, discharge to 2.7V at 40mA
Charge / discharge cycle test in a 20 ° C atmosphere
did. On the other hand, for the secondary battery of Example 6, the charging current
After charging to 4.0 V at 40 mA for 5 hours, at 40 mA
A charge / discharge cycle test for discharging to 2.7 V was performed in a 20 ° C atmosphere.
1 in each charge and discharge Asahi cycle test
Cycle discharge capacity (initial capacity) and 300 cycles
Table 2 below shows the capacity maintenance rate (relative to the initial capacity) at the time.
Shown in Examples 1 to 5, 7 to 9 and Comparative Example 1
4.2 V at a charging current of 40 mA for the secondary batteries
After charging for 5 hours, the battery was discharged to 2.7V at 2C.
The discharge capacity was measured, and the capacity retention rate at 2C discharge rate (2
The ratio of the discharge capacity to the initial capacity at C) is calculated.
Are also shown in Table 2 below. On the other hand, the secondary
For the pond, charging current of 40 mA to 4.0 V for 5 hours
Discharge capacity when discharged to 2.7V at 2C after charging
Is measured to calculate the capacity retention at the 2C discharge rate, and
Are also shown in Table 2 below. Further, Examples 1 to 5, 7 to 9 and Comparative Example
Charge the secondary batteries 1 to 3 in an atmosphere of 20 ° C.
After charging to 4.2 V for 5 hours with a current of 40 mA,
Discharge to 2.7 V at 40 mA in an atmosphere of
The discharge capacity was measured and the capacity retention rate at 0 ° C discharge (0 ° C
Ratio of the discharge capacity to the initial capacity).
Are also shown in Table 2 below. On the other hand, the secondary battery of Example 6
At a charging current of 40 mA in an atmosphere of 20 ° C.
After charging to 4.0 V for 5 hours, in an atmosphere of 0 ° C.
The discharge capacity at the time of discharging to 2.7 V at 40 mA was measured.
To calculate the discharge capacity retention rate at 0 ° C discharge.
Also shown in Table 2. [Table 1] [Table 2] As is clear from Tables 1 and 2, the secondary of Examples 1 to 9 was used.
The battery discharges with a large current of 2C, initial capacity, cycle life.
At the same time and the discharge capacity at a low temperature of 0 ° C.
You can see that you can do it. In particular, Example 1, Example 2, Implementation
The secondary battery of Example 9 has excellent performance compared to other secondary batteries.
You can see that there is. On the other hand, the secondary battery of Comparative Example 1
Despite its excellent capacity, it has a cycle life of 2C
Discharge capacity when charging and discharge capacity at low temperature of 0 ° C
It turns out that it is lower than the secondary batteries of Examples to 9. Also, the ratio
The secondary battery of Comparative Example 2 was discharged with a large current of 2 C in initial capacity.
Example 1 shows the discharge capacity at the time of discharge and the discharge capacity at a low temperature of 0 ° C.
9 are lower than those of the secondary batteries of No. 9 to No. 9. The battery performance of Comparative Example 3 was the same as that of Example 1.
However, a short circuit occurred in a drop test from
I can no longer move. For 3C rate overcharge test
Short-circuiting occurs early, and the battery heats up rapidly,
Eruption and liquid leakage occurred. On the other hand, Examples 1 to 8
No problem occurred in both drop test and overcharge test.
In particular, Example 9 was excellent in battery strength and safety. Embodiment 10 A positive electrode similar to that described in Example 1 above.
A negative electrode similar to that described in Example 1 and 120 ° C. for 1 hour
Heat shrinkage at 10%, thickness 25μm, porosity
Multilayer structure of 50% polyethylene / polypropylene
Using a separator consisting of a porous film having
An electrode group was formed in the same manner as described in the first embodiment.
The same non-aqueous electrolyte as described in Example 1 and the electrode group was used.
The solution was stored in a laminate film, and
With the structure shown, the non-aqueous electrolyte per 1 Ah of battery capacity is
4.5, thickness 0.5mm, length 54mm, width 86
mm thin non-aqueous electrolyte secondary battery was assembled. Embodiments 11 to 15 Heat shrinkage at 120 ° C for 1 hour in separator, thickness
Except that the hardness and porosity are set to the values shown in Table 3 below.
Thin non-aqueous electrolyte secondary battery having the same configuration as that of Embodiment 10 described above.
Assembled the pond. Embodiments 16 and 17 Heat separator at 120 ° C for 1 hour, thickness as separator
Polypropylene whose hardness and porosity are the values shown in Table 3 below
Example 10 described above, except that a porous film made of
A thin non-aqueous electrolyte secondary battery having the same configuration as that of was assembled. Embodiment 18 Heat treatment was performed at 1100 ° C. as a carbonaceous material for the negative electrode
Petroleum coke (average particle size is 5μm, average spacing (d
₀₀₂) Is 0.355 nm and the specific surface area by the BET method is 1
Same as Example 10 described above except that 0 m2 / g was used.
Such a thin non-aqueous electrolyte secondary battery was assembled. Embodiment 19 Natural graphite (average particle size of 7μm
And the average surface spacing (d_{00 2}) Is 0.3355 nm, BET
3m specific surface area²/ G except
Thin non-aqueous electrolyte secondary battery having the same configuration as that of Embodiment 10 described above.
Assembled the pond. About the obtained secondary batteries of Examples 10 to 19,
The battery was charged to 4.2 V at a charging current of 40 mA for 5 hours.
After that, charge and discharge cycle test to discharge to 2.7 V at 40 mA
The experiment was performed in a 20 ° C. atmosphere. 1st cycle
Discharge capacity (initial capacity) and capacity at 300 cycles
The amount retention ratio (based on the initial capacity) is shown in Table 4 below. The secondary batteries of Examples 10 to 19 are also described.
After charging for 5 hours to 4.2V with a charging current of 40 mA,
The discharge capacity at the time of discharging to 2.7 V at C was measured.
Capacity retention rate at discharge rate (the initial value of discharge capacity at 2C)
Ratio to the initial capacity), and the results are shown in Table 4 below.
I will write it together. Further, with respect to the secondary batteries of Examples 10 to 19,
And 4.2 V at a charging current of 40 mA in an atmosphere of 20 ° C.
After charging for 5 hours, it is 40 mA in an atmosphere of 0 ° C.
The discharge capacity at the time of discharging to 2.7 V was measured at 0 ° C.
Discharge capacity retention rate in electricity (initial capacity of discharge capacity at 0 ° C
Ratio), and the results are shown in Table 4 below.
You. Table 4 also shows the results of Comparative Example 2 described above.
You. [Table 3] [Table 4]As is clear from Tables 3 and 4, Examples 10 to 19
The secondary battery has a higher initial capacity and size compared to the secondary battery of Comparative Example 2.
Outstanding service life and discharge capacity when discharged with a large current of 2C
You can see that it is. In particular, in Examples 10 and 17
Rechargeable batteries have better performance than other rechargeable batteries
I understand. Embodiment 20 <Preparation of Positive Electrode> First, lithium cobalt oxide (Li_x
CoO₂X is 0 ≦ X ≦ 1) powder 91 weight
% Acetylene black 3.5% by weight, graphite
3.5% by weight and ethylene propylene diene monomer powder
2% by weight and toluene are added and mixed together, 10cm²This
Pores with 0.5mm diameter holes at a rate of 10 pieces
Of current collector made of high quality aluminum foil (thickness 20μm)
After coating on the surface, press the electrode density to 3g
/ Cm³The positive electrode having a structure in which the positive electrode layer is supported by the current collector is
Produced. The size of the positive electrode is 45 mm long and 75 mm wide
Met. <Production of negative electrode> Heat treatment at 3000 ° C. as carbonaceous material
Mesophase pitch based carbon fiber (fiber diameter 8μm, flat
The average fiber length is 20 μm and the average spacing (d₀₀₂) Is 0.33
60nm, BET specific surface area 2m²/ G) powder
93% by weight of powder and polyvinylidene fluoride as binder
(PVdF) as a current collector by mixing with 7% by weight.
10cm²0.5 mm diameter holes at a rate of 10 per hole
Coated on one side of porous copper foil (16μm thick) with
, Dried and pressed to give an electrode density of 1.3 g
/ Cm³Thus, a negative electrode having a structure in which the negative electrode layer is supported by a current collector is used.
Produced. The size of the negative electrode is 46 mm long and 76 mm wide
Met. <Separator> As a separator, the thickness is 25 μm,
10% heat shrinkage at 120 ° C for 1 hour and 50% porosity
A polyethylene porous film was prepared. Separator
Was 48 mm long and 78 mm wide. This big
When laminated with the positive and negative electrodes, the four sides are all positive.
The length that extends from the positive and negative electrodes,
1.5 mm width each, 1 mm from the negative electrode
Size. <Preparation of electrode group> Using the positive electrode, the negative electrode and the separator
Other than that, the same as described in the first embodiment
An electrode group was produced by the method. The electrode group and the first embodiment will be described.
Non-aqueous electrolyte similar to that stored in a laminate film
And has the structure shown in FIG. 1 described above, and has a battery capacity of 1 Ah.
Non-aqueous electrolyte volume is 5.0 g, thickness is 0.5 mm, width
Thin non-aqueous electrolyte secondary battery with a height of 54 mm and a height of 86 mm
Was assembled. Embodiment 21 10cm as positive electrode current collector²5 pieces per diameter
Porous aluminum foil with 0.5 mm holes (thickness
Is 230 μm), and 10 cm is used as a negative electrode current collector. ²This
Porous with 0.5 mm diameter holes at a ratio of 5 pieces
Except for using copper foil (thickness 20μm),
Assembling a thin non-aqueous electrolyte secondary battery having the same configuration as in Example 20
I was Embodiment 22 Non-porous aluminum with a thickness of 50 μm as a positive electrode current collector
Using foil, 10cm as negative electrode current collector²15 per
Porous copper foil (thickness: 0.3 mm in diameter)
Is 20 μm) except that Example 20 described above is used.
A thin non-aqueous electrolyte secondary battery having a similar configuration was assembled. Embodiment 23 Non-porous aluminum with a thickness of 60 μm as a positive electrode current collector
Using foil, 10cm as negative electrode current collector²5 pieces per
Porous copper foil (having a thickness of 16 mm)
μm), except that μm) is used.
A thin non-aqueous electrolyte secondary battery having such a configuration was assembled. Embodiment 24 Non-porous aluminum with a thickness of 15 μm as a positive electrode current collector
Using foil, 10cm as negative electrode current collector²One per one
Porous copper foil (thickness of 16 mm)
μm) is the same as in Example 20 described above.
A thin non-aqueous electrolyte secondary battery having such a configuration was assembled. Embodiment 25 Non-porous aluminum with a thickness of 30 μm as a positive electrode current collector
Using foil, 10cm as one negative electrode current collector²5 per
Porous copper foil having a hole with a diameter of 4 mm
6 μm), except that
A thin non-aqueous electrolyte secondary battery having a similar configuration was assembled. Embodiment 26 10cm as positive electrode current collector²2 pieces per diameter
Porous aluminum foil with 0.3 mm holes (thickness
Is 20 μm) and the thickness of the negative electrode current collector is 16 μm.
Except for using non-porous copper foil,
A thin non-aqueous electrolyte secondary battery having the same configuration as that of was assembled. Embodiment 27 10cm as positive electrode current collector²10 pieces per diameter 1
Porous aluminum foil with 20 mm holes (thickness of 20μ)
m), non-porous copper having a thickness of 16 μm as a negative electrode current collector
Except that a foil is used, the structure is the same as that of Example 20 described above.
Assemble a thin, non-aqueous electrolyte secondary battery. Embodiment 28 10cm as positive electrode current collector²1 piece per diameter 3
Porous aluminum foil with 20 mm holes (thickness of 20μ)
m), non-porous copper with a thickness of 16 μm as a negative electrode current collector
Except that a foil is used, the structure is the same as that of Example 20 described above.
A thin non-aqueous electrolyte secondary battery was assembled. Embodiment 29 10cm as positive electrode current collector²4 diameters per piece
mm porous aluminum foil (thickness of 15μ)
m), non-porous copper foil with a thickness of 16μm as a negative electrode current collector
Except that the same configuration as that of the above-described embodiment 20 is used.
The thin non-aqueous electrolyte secondary battery was assembled. Embodiment 30 Non-porous aluminum with a thickness of 15 μm as a positive electrode current collector
Using foil, non-porous copper with a thickness of 16μm as a negative electrode current collector
Except that a foil is used, the structure is the same as that of Example 20 described above.
A thin non-aqueous electrolyte secondary battery was assembled. Fruit obtained
Positive electrode current collector and negative electrode for secondary batteries of Examples 20 to 30
Table 5 shows the shape of the current collector. The secondary batteries of Examples 20 to 30 obtained were
After charging for 3 hours to 4.2V with a charging current of 60mA,
Charge / discharge cycle test to discharge to 2.7V
Discharge capacity at cycle (initial capacity) and at 500 cycles
Table 6 below shows the capacity retention ratio (based on the initial capacity) in
Shown in [Table 5] [Table 6] As is clear from Tables 5 and 6, Examples 20 to Example
30 rechargeable batteries have excellent initial capacity and cycle life
You can see that it is. In particular, Examples 20 and 22
Rechargeable batteries have better performance than other rechargeable batteries.
You can see that In the above-described embodiment, the positive electrode,
An electrode group was prepared using one separator and one negative electrode
However, an electrode group is formed using a plurality of positive electrodes, separators and negative electrodes.
It may be produced. In the above-described embodiment, the metal
Cylindrical non-aqueous electrolyte secondary battery with a bottomed cylindrical container
Although the example of application was explained, a metal bottomed rectangular cylindrical container was
The same applies to prismatic non-aqueous electrolyte secondary batteries
Can be. [0115] As described in detail above, according to the present invention,
Excellent capacity, cycle performance, large current discharge characteristics and low temperature discharge
While maintaining electrical characteristics, use a thin structure with a thickness of 3 mm or less.
To provide a non-aqueous electrolyte secondary battery and a method of manufacturing the same.
Can be offered.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an example of a non-aqueous electrolyte secondary battery according to the present invention. FIG. 2 is an enlarged sectional view showing a portion A in FIG. 1; DESCRIPTION OF REFERENCE NUMERALS 1 ... exterior material 2 ... electrode group 3 ... positive electrode current collector 4 ... positive electrode layer 5 ... positive electrode 6 ... negative electrode current collector 7 ... negative electrode layer 8 ... negative electrodes 9 a and 9 b ... porous adhesive layer 10 ... Separator 11 Positive electrode terminal 12 Negative electrode terminal

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Motoi Kanda 72 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Toshiba Corporation Kawasaki Office (56) References JP-A-10-172606 (JP, A) JP-A-10 JP-177865 (JP, A) JP-A-10-17237 (JP, A) JP-A-2-12761 (JP, A) JP-A-10-214615 (JP, A) JP-A-10-284056 (JP, A) JP-A-10-326628 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 10/40 H01M 4/00-4/62

Claims (1)

(57) [Claim 1] At least one end of a positive electrode between a positive electrode and a negative electrode
And an electrode group with a separator extending from the negative electrode
The step of producing, and the polymer having adhesiveness is dissolved in 0.1 to 2.5% by weight.
Impregnating the electrode group with the solution thus obtained, and subjecting the electrode group to vacuum drying so that the gap between the positive electrode and the separator is removed.
And forming a porous adhesive layer between the negative electrode and the separator.
And a step of impregnating the electrode group with a non-aqueous electrolyte.
A method for producing a non-aqueous electrolyte secondary battery, comprising: