JP7101733B2 - A method for manufacturing a recycled electrode active material for a lithium ion battery, a method for manufacturing a solution containing metal ions, a method for manufacturing a lithium ion battery, a recycled sheet-shaped electrode member for a lithium ion battery, and a method for manufacturing a recycled electrode sheet for a lithium ion battery. - Google Patents

Description

The present invention relates to a method for manufacturing a recycled electrode active material for a lithium ion battery, a method for manufacturing a solution containing metal ions, a method for manufacturing a lithium ion battery, a recycled sheet-shaped electrode member for a lithium ion battery, and a recycled electrode sheet for a lithium ion battery. Regarding the manufacturing method.

Lithium-ion (secondary) batteries have been widely used in various applications in recent years as high-capacity, compact and lightweight secondary batteries. In a general lithium ion battery, a positive electrode active material layer containing a positive electrode active material and an electrolytic solution and a negative electrode active material layer containing a negative electrode active material and an electrolytic solution are housed in a container with a separator sandwiched between them. It is configured.

Nickel oxide or cobalt oxide is often used as the material for the positive electrode active material. Metals such as nickel and cobalt are expensive, and if they are discarded as they are, they impose an environmental burden, so it is desired to recycle them for use.

Patent Document 1 describes a technique relating to a method for recovering a positive electrode active material from a waste lithium ion battery or a waste electrode material.
In Patent Document 1, after separating and removing the separator from the crushed material obtained by crushing the waste lithium ion battery or the waste electrode material, the organic matter contained in the binder is removed by heating at 400 to 550 ° C. in the atmosphere. It is stated that it should be done.

Japanese Unexamined Patent Publication No. 2012-195073 Japanese Unexamined Patent Publication No. 2016-186118

In the technique described in Patent Document 1, a waste lithium ion battery or a waste electrode material is crushed and heated (calcined) at 400 to 550 ° C.
With such a technique, there is a problem that the process of separating and recovering the active material is complicated.
Further, when the waste lithium ion battery or the waste electrode material is heated at 400 to 550 ° C., the electrolyte salt is thermally decomposed and fluorine-containing gas (HF) is generated. Therefore, it is essential to install an exhaust gas treatment device. There was also the problem of becoming.

Further, as described in Patent Document 2, the particle size of the positive electrode active material in the powdery or granular lithium ion battery scrap obtained by roasting, crushing and sieving the battery is such that the positive electrode active material is a binder resin. It is obtained in the state of bonded coarse particles (for example, particles having a particle diameter of more than 1 mm).
Since the surface area of these coarse particles is not so large, the ion extraction efficiency at the time of acid leaching with an acidic solution is poor, and it has been desired to perform more efficient ion extraction.

The present invention has been made to solve the above problems, and is a method for producing a regenerated electrode active material for a lithium ion battery from a lithium ion battery in a simple process without requiring high temperature heating, for the lithium ion battery. A method for producing a solution containing metal ions constituting the electrode active material from the regenerated electrode active material, a lithium ion battery suitable for the method for producing the regenerated electrode active material for the lithium ion battery, and high temperature heating are not required. It is an object of the present invention to provide a method for manufacturing a regenerated sheet-shaped electrode member for a lithium ion battery and a regenerated electrode sheet for a lithium ion battery from a lithium ion battery by a simple process.

The present invention comprises a first electrode active material layer comprising a first electrode composition containing a first current collector and a first electrode active material formed on the first current collector. A second electrode active material layer comprising a second electrode composition containing the electrode, the second current collector, and the second electrode active material formed on the second current collector. A power storage element including an electrode and a separator arranged between the first electrode active material layer and the second electrode active material layer is provided, and the first current collector is placed on the electrode. In the outer peripheral edge portion where the first electrode active material layer is not formed, from the lithium ion battery bonded to the separator via the first sealing material, the first sealing material is used as a boundary. A method for producing a regenerated electrode active material for a lithium ion battery, which comprises a taking-out step of separating the current collector of 1 and the separator to take out the first electrode active material; the lithium ion battery of the present invention. A dispersion preparation step of dispersing the regenerated electrode active material produced by the method for producing a regenerated electrode active material for use in a solvent containing water to obtain an electrode active material dispersion, and an aqueous solution separated from the electrode active material dispersion. Production of a solution containing metal ions of metal elements constituting the electrode active material having a pH adjusting step of adjusting the pH of the electrode active material dispersion so that the hydrogen ion index (pH) at 25 ° C. is 5 or less. Method; A first electrode comprising a first electrode active material layer comprising a first electrode composition comprising a first current collector and a first electrode active material formed on the first current collector. A second electrode comprising a second electrode active material layer composed of a second electrode active material and a second electrode composition containing the second current collector and the second electrode active material formed on the second current collector. A lithium ion battery including a power storage element including a separator arranged between the first electrode active material layer and the second electrode active material layer, and the first current collector is In the outer peripheral edge portion on which the first electrode active material layer is not formed, the separator is adhered to the separator via the first sealing material, and the second electrode current collector is placed on the separator. At the outer peripheral edge portion where the second electrode active material layer is not formed, the resin is adhered to the separator via the second sealing material, and the melting point of the resin constituting the first sealing material is less than 200 ° C. The lithium ion battery is characterized in that the melting point of the resin constituting the second sealing material is higher than the melting point of the resin constituting the first sealing material by 30 ° C. or more; On the first current collector above On the first electrode having the first electrode active material layer made of the first electrode composition containing the first electrode active material formed in, the second current collector, and the second current collector. A second electrode comprising a second electrode active material layer composed of a second electrode composition containing the second electrode active material formed in the above, the first electrode active material layer, and the second electrode active material. A lithium ion battery including a power storage element composed of a separator arranged between the material layer, and the first current collector is outside the first electrode active material layer on which the first electrode active material layer is not formed. In the peripheral edge portion, the separator is adhered to the separator via the first sealing material, and the second electrode current collector is formed in the outer peripheral edge portion on which the second electrode active material layer is not formed. , The separator is adhered to the separator via the second sealing material, and the SP values and Tg of the first sealing material and the second sealing material satisfy all of the following conditions (1) and (2). A lithium-ion battery characterized by that.
Condition (1): [Absolute value of the difference between the SP value of the resin constituting the first sealing material and the SP value of the resin constituting the second sealing material]> 3.5
Condition (2): [Absolute value of the difference between Tg of the resin constituting the first sealing material and Tg of the resin constituting the second sealing material] ≧ 35; A first electrode having a first electrode active material layer composed of a first electrode composition containing a first electrode active material formed on a current collector, a second current collector, and the second collection described above. A second electrode including a second electrode active material layer made of a second electrode composition containing a second electrode active material formed on an electric body, and the first electrode active material layer and the first electrode active material layer. An outer peripheral edge portion provided with a power storage element composed of a separator arranged between the two electrode active material layers, and the first current collector is not formed on the first electrode active material layer. In the lithium ion battery bonded to the separator via the first sealing material, the first current collector and the separator are separated from the lithium ion battery with the first sealing material as a boundary. A method for manufacturing a recycled sheet-shaped electrode member for a lithium ion battery, which comprises a taking-out step of taking out a first recycled sheet-shaped electrode member including the current collector 1 and the first electrode active material layer; And; a first electrode comprising a first electrode active material layer comprising a first electrode composition comprising a first current collector and a first electrode active material formed on the first current collector. , A second electrode comprising a second electrode active material layer comprising a second electrode active material comprising a second current collector and a second electrode active material formed on the second current collector. Further, the storage element including the separator disposed between the first electrode active material layer and the second electrode active material layer is provided, and the first current collector is placed on the first electrode active material layer. In the outer peripheral edge portion where the electrode active material layer is not formed, the separator is adhered to the separator via the first sealing material, and the second current collector is placed on the second electrode active material. In the outer peripheral edge portion where the layer is not formed, the lithium ion battery bonded to the separator via the second sealing material is separated from the second current collector with the second sealing material as a boundary. It is characterized by having a take-out step of taking out a first regenerated electrode sheet composed of the first current collector, the first electrode active material layer, the separator and the first sealing material by separating from the separator. The present invention relates to a method for manufacturing a recycled electrode sheet for a lithium ion battery.

According to the present invention, a method for producing a regenerated electrode active material for a lithium ion battery from a lithium ion battery, which does not require high temperature heating and in a simple process, constitutes an electrode active material from the regenerated electrode active material for the lithium ion battery. A lithium ion battery suitable for a method for producing a solution containing metal ions, a method for producing a regenerated electrode active material for a lithium ion battery, and a lithium ion battery from a lithium ion battery in a simple process that does not require high temperature heating. It is possible to provide a method for manufacturing a recycled electrode member for a recycled sheet and a recycled electrode sheet for a lithium ion battery.

FIG. 1 is a sectional view schematically showing an example of a lithium ion battery used in the method for producing a recycled electrode active material for a lithium ion battery of the present invention. FIG. 2A is a perspective view schematically showing the first electrode constituting the power storage element shown in FIG. 1, and FIG. 2B is a second electrode constituting the power storage element shown in FIG. It is a perspective view which shows schematically. FIG. 3 is a cross-sectional view schematically showing an example of the taking-out process. FIG. 4 is a cross-sectional view schematically showing another example of the extraction process. FIG. 5 is a cross-sectional view schematically showing still another example of the extraction process. FIG. 6 is a schematic diagram showing an example of a method for separating the first electrode active material from the recycled sheet-shaped electrode member for a lithium ion battery. FIG. 7 is a cross-sectional view schematically showing an example of a take-out process in the method for manufacturing a recycled electrode sheet for a lithium ion battery of the present invention.

Hereinafter, the present invention will be described in detail.
In the present specification, when the term lithium ion battery is used, the concept includes a lithium ion secondary battery. Further, the electrode active material taken out from the lithium ion battery is referred to as a regenerated electrode active material to distinguish it from the electrode active material used in manufacturing the lithium ion battery, and the regenerated electrode active material is at least a current collector and a separator. Those combined with one of them are referred to as recycled sheet-shaped electrode members to distinguish them from the sheet-shaped electrode members used in manufacturing lithium-ion batteries. Further, a combination of the regenerated electrode active material with a current collector and a separator is referred to as a regenerated electrode sheet to distinguish it from an electrode used in manufacturing a lithium ion battery.

[Manufacturing method of regenerated electrode active material for lithium-ion batteries]
The method for producing a regenerated electrode active material for a lithium ion battery of the present invention is from a first electrode composition containing a first current collector and a first electrode active material formed on the first current collector. Consists of a second electrode composition comprising a first electrode comprising a first electrode active material layer, a second current collector, and a second electrode active material formed on the second current collector. A power storage element including a second electrode provided with a second electrode active material layer and a separator arranged between the first electrode active material layer and the second electrode active material layer is provided. From the lithium ion battery in which the first current collector is adhered to the separator via the first sealing material in the outer peripheral edge portion where the first electrode active material layer is not formed on the collector. It is characterized by having a take-out step of separating the first current collector and the separator and taking out the first electrode active material with the first sealing material as a boundary.

In the method for producing a regenerated electrode active material for a lithium ion battery of the present invention, a first regenerated electrode active material is obtained by separating the first current collector and the separator with the first sealing material as a boundary. The electrode active material can be taken out from the lithium ion battery.
Since the first sealing material is a resin that adheres the first current collector and the separator, the first current collector is separated from the first sealing material without heating at a high temperature of 400 to 550 ° C. And the separator can be separated. Therefore, the process becomes simple and the recycling cost can be suppressed. Further, since the obtained recycled electrode active material is difficult to be sintered, a recycled electrode active material having a large specific surface area can be obtained. The regenerated electrode active material having a large specific surface area has high ion extraction efficiency and is suitable for recycling.

[Lithium-ion battery]
First, the configuration of the lithium ion battery used in the method for producing the regenerated electrode active material for a lithium ion battery of the present invention will be described with reference to FIGS. 1, 2 (a) and 2 (b).
FIG. 1 is a sectional view schematically showing an example of a lithium ion battery used in the method for producing a regenerated electrode active material for a lithium ion battery of the present invention, and FIG. 2A shows a power storage element shown in FIG. 2 is a perspective view schematically showing a first electrode constituting, and FIG. 2B is a perspective view schematically showing a second electrode constituting the power storage element shown in FIG. 1.
As shown in FIG. 1, the lithium ion battery 1 has a first electrode active material layer 13 containing a first current collector 11 and a first electrode active material formed on the first current collector 11. The first electrode 10 including the above, the second current collector 21, and the second electrode active material layer 23 containing the second electrode active material formed on the second current collector 21 are included. The second electrode 20 and the second electrode 20 are arranged so as to face each other via the separator 30 to form a power storage element 40, and the outside of the power storage element 40 is covered with the battery exterior body 50.

An insulating layer (not shown) is formed on the inner surface of the battery exterior body 50, and the first current collector 11 and the second current collector 21 are insulated from each other. Further, an external electrode (not shown) is connected to the first current collector 11 and the second current collector 21, and a part of the external electrode is pulled out to the outside of the battery exterior body 50.

As shown in FIG. 2A, when the power storage element 40 is viewed along the direction in which the first current collector 11 and the second current collector 21 face each other, the outside of the first current collector 11 The peripheral portion is not provided with the first electrode active material layer 13, but is provided with the first sealing material 15. Then, the first current collector 11 and the separator (not shown) are adhered to each other via the first sealing material 15 provided on the outer peripheral edge portion. As shown in FIGS. 1 and 2A, the first electrode active material layer 13 is covered with the first current collector 11, the separator 30, and the first sealing material 15.
Therefore, when the first sealing material 15 adheres the separator 30 and the first current collector 11, the first electrode active material layer 13 is not exposed to the outside. In other words, by separating the first current collector 11 and the separator 30 with the first sealing material 15 as a boundary, the first electrode active material layer 13 can be taken out to the outside of the power storage element 40. ..

As shown in FIG. 2B, when the power storage element 40 is viewed along the direction in which the first current collector 11 and the second current collector 21 face each other, the outside of the second current collector 21 The second electrode active material layer 23 is not provided on the peripheral portion, and the second sealing material 25 is provided. Then, the second current collector 21 and the separator (not shown) are adhered to each other via the second sealing material 25. As shown in FIGS. 1 and 2B, the second electrode active material layer 23 is covered with the second current collector 21, the separator 30, and the second sealing material 25.

Although FIGS. 1 and 2 (b) have described an example in which the second collector 21 and the separator 30 are adhered to each other by the second sealing material 25, the lithium ion battery of the present invention is re-bonded. In the lithium ion battery used in the method for producing a living substance, the second sealing material is not essential, and the second current collector and the separator may be directly adhered to each other.
As a method of directly adhering the second current collector and the separator, for example, a method of thermocompression bonding the second current collector and the separator can be mentioned.

[Extraction process]
In the extraction step, the first current collector and the separator are separated from each other with the first sealing material as a boundary. By separating the first current collector and the separator with the first sealing material as a boundary, the first electrode active material arranged between the first current collector and the separator can be easily taken out. be able to.

As a method of separating the first current collector and the separator with the first sealing material as a boundary, for example, a method of heating a power storage element, a method of immersing the power storage element in a solvent, or a first seal. Examples include a method of cutting the material.
Hereinafter, as a first embodiment of the method for producing a regenerated electrode active material for a lithium ion battery of the present invention, an example of a method of heating a power storage element is an example of a method of immersing the power storage element in a solvent for the lithium ion battery of the present invention. As a second embodiment of the method for producing a regenerated electrode active material, an example of a method for cutting the first sealing material will be described as a third embodiment of the method for producing a regenerated electrode active material for a lithium ion battery of the present invention. ..

In the first embodiment of the method for producing a recycled electrode active material for a lithium ion battery of the present invention, the extraction step heats the power storage element at a temperature equal to or higher than the melting point of the resin constituting the first sealing material and lower than 200 ° C. It is preferable to have a process.
In the extraction process, the current collector is heated at a temperature equal to or higher than the melting point of the resin constituting the first sealing material and lower than 200 ° C. to soften the first sealing material and use the first sealing material as a boundary. The first current collector and the separator can be separated.

An example of the first embodiment of the method for producing a regenerated electrode active material for a lithium ion battery of the present invention will be described with reference to FIG.
FIG. 3 is a cross-sectional view schematically showing an example of the taking-out process.
In the extraction step shown in FIG. 3, the power storage element 40 is heated to separate the first current collector 11 and the separator 30 with the first sealing material 15 as a boundary.
The melting point of the first sealing material 15 is less than 200 ° C.
Therefore, after removing the battery exterior 50 from the lithium ion battery 1, the power storage element 40 is heated at a temperature equal to or higher than the melting point of the resin constituting the first sealing material 15 and lower than 200 ° C. to obtain the first sealing material. By softening 15 and separating the first current collector 11 and the separator 30 with the first sealing material 15 as a boundary, the first electrode active material layer 13 and the first current collector 11 are separated from each other. The first regenerated sheet-shaped electrode member 110 is obtained.

In the first embodiment of the method for producing a recycled electrode active material for a lithium ion battery of the present invention, the temperature at which the power storage element is heated (hereinafter, also referred to as the heating temperature) is the melting point of the resin constituting the first sealing material. As described above, the temperature may be lower than 200 ° C., but it is preferably 10 ° C. or higher, more preferably 20 ° C. or higher, and even more preferably 30 ° C. or higher than the melting point of the resin constituting the first sealing material.

In the first embodiment of the method for producing a recycled electrode active material for a lithium ion battery of the present invention, the melting point of the resin constituting the first sealing material is less than 200 ° C.
The resin constituting the first sealing material is preferably at least one selected from the group consisting of polyamide, polyvinylidene fluoride and polyolefin.

The first current collector may be a metal current collector made of metal, or may be a resin current collector made of a first matrix resin and a conductive filler (first resin current collector). ..

When the second current collector and the separator are adhered to each other by the second sealing material, the melting point of the resin constituting the second sealing material is higher than the melting point of the resin constituting the first sealing material. It is preferably higher than 30 ° C.
When the melting point of the resin constituting the second sealing material is 30 ° C. or higher higher than the melting point of the resin constituting the first sealing material, the temperature at which the first sealing material softens but the second sealing material does not soften. Easy to adjust. By heating the power storage element at a temperature at which the first sealing material softens but the second sealing material does not soften, the second sealing material does not soften and the first sealing material is used as a boundary. Since the current collector and the separator can be separated, only the first electrode active material can be selectively taken out.

The resin constituting the second sealing material is preferably at least one selected from the group consisting of polyamide, polyimide, polyvinylidene fluoride, polyester and polyolefin.
Since polyimide is a thermosetting resin, it does not have a melting point. In the present invention, the melting point of the resin constituting the second sealing material is the temperature at which embrittlement starts when the second sealing material is heated. Therefore, when the second sealing material is made of a resin having no melting point such as a thermosetting resin, the thermal decomposition temperature, which is the temperature at which brittleness starts, is set to the temperature of the resin constituting the second sealing material. Let it be the melting point.

In the second embodiment of the method for producing a regenerated electrode active material for a lithium ion battery of the present invention, the extraction step includes a step of immersing the power storage element in a solvent, and the SP value of the resin constituting the first sealing material is used. The absolute value of the difference from the SP value of the solvent is preferably 1.0 or less.
By setting the absolute value of the difference between the SP value of the resin constituting the first sealing material and the SP value of the solvent to 1.0 or less, the first sealing material is swelled and softened by the solvent, and the first seal material is swelled and softened. The first current collector and the separator can be separated from each other with the sealing material as a boundary.

The SP value [unit: (cal / cm ³ ) ^0.5 ] in the present invention was calculated by the method described in Volumer engineering and science Vol. 14, pp. 151-154 by Robert F Fedors et al. It is a value at 25 ° C.

An example of the second embodiment of the method for producing a regenerated electrode active material for a lithium ion battery of the present invention will be described with reference to FIG.
FIG. 4 is a cross-sectional view schematically showing another example of the extraction process.
In the extraction step shown in FIG. 4, the battery exterior 50 is removed from the lithium ion battery 1, and then the power storage element 40 is immersed in the solvent 60. At this time, by selecting the solvent so that the absolute value of the difference between the SP value of the resin constituting the first sealing material 15 and the SP value of the solvent 60 is 1.0 or less, the first seal material 60 is used. The sealing material 15 swells and softens. When the first sealing material 15 swells and softens, the first current collector 11 and the separator 30 are separated from each other with the first sealing material 15 as a boundary, and the first electrode active material layer 13 and the first are separated. A first regenerated sheet-shaped electrode member 110 made of the current collector 11 of 1 is obtained.

When the power storage element is immersed in a solvent in the extraction step, examples of the resin constituting the first sealing material include polyamide, polyvinylidene fluoride, and polyolefin.

In the case of the method of immersing the power storage element in the solvent, the second current collector and the separator may be adhered to each other by the second sealing material.
However, when the second current collector and the separator are adhered by the second sealing material, the SP value and Tg of the resin constituting the first sealing material and the resin constituting the second sealing material are used. However, it is preferable that both of the following conditions (1) and (2) are satisfied.
Condition (1): [Absolute value of the difference between the SP value of the resin constituting the first sealing material and the SP value of the resin constituting the second sealing material]> 3.5
Condition (2): [Absolute value of the difference between Tg of the resin constituting the first sealing material and Tg of the resin constituting the second sealing material] ≧ 35
The glass transition temperature (Tg) in the present invention is a value measured according to the differential scanning calorimetry (DSC) method described in JIS K 7121 (1987).

When the SP values and Tg of the resin constituting the first sealing material and the resin constituting the second sealing material satisfy both the above conditions (1) and (2), the first sealing material is formed. By utilizing the difference in physical properties between the resin and the resin constituting the second sealing material, only the first electrode active material can be selectively taken out.
Specifically, a solvent having a difference of less than 1.0 from the SP value of the resin constituting the first sealing material and a difference of more than 2.5 from the SP value of the resin constituting the second sealing material. By immersing the power storage element in the solvent, only the resin constituting the first sealing material can be swollen and softened, and it becomes easy to selectively take out only the first electrode active material.

Further, when the second current collector and the separator are adhered to each other by the second sealing material, it is preferable that the following condition (3) is further satisfied.
Condition (3): [Absolute value of the difference between the SP value of the separator and the SP value of the resin constituting the second sealing material] ≦ 1.0
When the above condition (3) is satisfied, the separator becomes less soluble in the solvent as in the second sealing material.

Examples of the solvent used when the power storage element is immersed in the solvent include xylene (SP value: 8.8), DMF (SP value: 12.0) and the like.

The temperature of the solvent when the power storage element is immersed in the solvent is not particularly limited, but is preferably 140 to 150 ° C.

In the third embodiment of the method for producing a recycled electrode active material for a lithium ion battery of the present invention, the extraction step is a direction in which the first sealing material is substantially perpendicular to the direction in which the first current collector and the separator face each other. It is preferable to have a step of cutting along the above.

An example of the third embodiment of the method for producing a regenerated electrode active material for a lithium ion battery of the present invention will be described with reference to FIG.
FIG. 5 is a cross-sectional view schematically showing still another example of the extraction process.
After removing the battery exterior body 50 from the lithium ion battery 1, the first sealing material 15 constituting the power storage element 40 is cut in a direction substantially perpendicular to the direction in which the first current collector 11 and the separator 30 face each other. (Cut at the position indicated by the alternate long and short dash line in FIG. 5) to divide the first sealing material 15 itself. By dividing the first sealing material 15, the first current collector 11 and the separator 30 are separated, and the first electrode active material layer 13 and the first current collector 11 are composed of the first current collector 11. A recycled sheet-shaped electrode member 110 is obtained.

In the third embodiment of the method for producing a recycled electrode active material for a lithium ion battery of the present invention, the type of resin constituting the first sealing material is not particularly limited, but polyolefin is preferable.

In the third embodiment of the method for producing a regenerated electrode active material for a lithium ion battery of the present invention, the first sealing material is cut along a direction substantially perpendicular to the direction in which the first current collector and the separator face each other. As a method of doing so, for example, a method using a blade, a laser cutter, or the like can be mentioned. The blade may be made of metal or non-metal (eg, ceramic).

The recycled sheet-shaped electrode member 110 obtained by the methods shown in FIGS. 3 to 5 includes a first electrode active material layer 13 and a first current collector 11.
In the method for producing a recycled electrode active material for a lithium ion battery of the present invention, the first electrode active material layer 13 is further separated from the recycled sheet-shaped electrode member 110 in the extraction step.

FIG. 6 is a schematic diagram showing an example of a method for separating the first electrode active material from the recycled sheet-shaped electrode member for a lithium ion battery.
As shown in FIG. 6, the regenerated electrode active material containing the first electrode active material is scraped off by scraping the first electrode active material layer 13 formed on the first current collector 11 with a squeegee 90 or the like. 14 can be recovered.
Further, in the method shown in FIG. 4, the first electrode active material layer 13 and the first current collector 11 can be separated by dispersing the first electrode active material layer 13 in the solvent 60. Even in such a case, the regenerated electrode active material can be recovered.

The use of the regenerated electrode active material for a lithium ion battery obtained by the method for producing a regenerated electrode active material for a lithium ion battery of the present invention is not particularly limited, but for example, it is a raw material for an electrode active material layer when manufacturing a lithium ion battery. The metal may be recovered by acid extraction or the like.

When the step shown in FIG. 6 is not performed after the steps shown in FIGS. 3 to 5, the steps shown in FIGS. 3 to 5 are the same as the method for manufacturing a recycled sheet-shaped electrode member for a lithium ion battery of the present invention, which will be described later. Become.

Subsequently, the configuration of the lithium ion battery used in the method for producing the regenerated electrode active material for a lithium ion battery of the present invention will be described.

[Construction of lithium-ion battery]
The lithium ion battery used in the method for producing a regenerated electrode active material for a lithium ion battery of the present invention contains a first current collector and a first electrode active material formed on the first current collector. A second electrode including a first electrode including a first electrode active material layer made of the electrode composition 1, a second current collector, and a second electrode active material formed on the second current collector. A storage element including a second electrode provided with a second electrode active material layer made of the above-mentioned electrode composition, and a separator arranged between the first electrode active material layer and the second electrode active material layer. The first current collector is bonded to the separator via the first sealing material at the outer peripheral edge portion where the first electrode active material layer is not formed on the collector.

[First electrode]
The first electrode includes a first current collector and a first electrode active material layer containing the first electrode active material formed on the first current collector.

The first current collector may be a metal current collector made of metal, or may be a resin current collector made of a first matrix resin and a conductive filler (first resin current collector). However, it is preferable that the resin collector (first resin collector) is used.

The thickness of the first current collector is not particularly limited, but is preferably 5 to 150 μm.

As the metal collector, copper, aluminum, titanium, stainless steel, nickel, alloys thereof and the like can be used.

The conductive filler is selected from materials having conductivity.
Specifically, metals [nickel, aluminum, stainless steel (SUS), silver, copper, titanium, etc.], carbon [graphite and carbon black (acetylene black, ketjen black, furnace black, channel black, thermal lamp black, etc.), etc.), etc. ], And a mixture thereof, etc., but carbon is preferable. When the conductive filler is carbon, it is possible to prevent the metal derived from the first current collector from being mixed in the extracted first electrode active material. This is effective as a method of suppressing deterioration of the characteristics of the first electrode active material taken out when the first electrode active material is a positive electrode active material.
These conductive fillers may be used alone or in combination of two or more. Moreover, you may use these alloys or metal oxides. From the viewpoint of electrical stability, aluminum, stainless steel, carbon, silver, copper, titanium and a mixture thereof are preferable, silver, aluminum, stainless steel and carbon are more preferable, and carbon is more preferable. Further, as these conductive fillers, a particle-based ceramic material or a resin material may be coated with a conductive material (a metal material among the above-mentioned conductive filler materials) by plating or the like.

The average particle size of the conductive filler is not particularly limited, but is preferably 0.01 to 10 μm, more preferably 0.02 to 5 μm, and 0, from the viewpoint of the electrical characteristics of the battery. It is more preferably 3.03 to 1 μm. In addition, in this specification, "particle diameter" means the maximum distance L among the distances between arbitrary two points on the contour line of a particle. As the value of the "average particle size", an observation means such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM) is used, and the average value of the particle size of the particles observed in several to several tens of fields is used. The calculated value shall be adopted.

The shape (form) of the conductive filler is not limited to the particle form, and may be a form other than the particle form, or may be a form practically used as a so-called filler-based conductive resin composition such as carbon nanotubes. good.

The conductive filler may be a conductive fiber whose shape is fibrous.
As the conductive fiber, a carbon fiber such as a PAN-based carbon fiber or a pitch-based carbon fiber, a conductive fiber obtained by uniformly dispersing a metal having good conductivity or graphite in a synthetic fiber, or a metal such as stainless steel is used. Examples thereof include fibrous metal fibers, conductive fibers in which the surface of organic fibers is coated with metal, and conductive fibers in which the surface of organic fibers is coated with a resin containing a conductive substance. Among these conductive fibers, carbon fiber is preferable. Further, a polypropylene resin kneaded with graphene is also preferable.
When the conductive filler is a conductive fiber, the average fiber diameter thereof is preferably 0.1 to 20 μm.

The weight ratio of the conductive filler in the first resin current collector is preferably 5 to 90% by weight, more preferably 20 to 80% by weight.
In particular, when the conductive filler is carbon, the weight ratio of the conductive filler is preferably 20 to 30% by weight.

The melting point of the first matrix resin is preferably less than 200 ° C.
Examples of the first matrix resin having a melting point of less than 200 ° C. include polyamide, polyolefin, polyvinylidene fluoride and the like.
Further, the first matrix resin is preferably at least one selected from the group consisting of polyamide, polyolefin and polyvinylidene fluoride.
The melting point of the polyolefin is about 95-140 ° C.
The melting point of polyvinylidene fluoride is about 150 to 180 ° C.
In the present specification, the melting point of the first matrix resin uses a numerical value measured according to the differential scanning calorimetry (DSC) method described in JIS K 7121-1987.

The first resin current collector contains other components (dispersant, cross-linking accelerator, cross-linking agent, colorant, ultraviolet absorber, plasticizer, etc.) in addition to the first matrix resin and the conductive filler. You may.

The thickness of the first resin current collector is not particularly limited, but is preferably 5 to 400 μm.

The first resin current collector can be obtained, for example, by forming a conductive resin composition obtained by melt-kneading the first matrix resin and the conductive filler into a film shape.
Examples of the method for forming the conductive resin composition into a film include known film forming methods such as a T-die method, an inflation method, and a calendar method. The first resin current collector can also be obtained by a molding method other than film molding.

The first electrode active material layer comprises a first electrode composition containing the first electrode active material.
The first electrode active material layer is preferably a non-binding body that does not contain a binder that binds the first electrode active materials to each other.
Here, the non-bonded body means that the first electrode active materials are not bonded to each other, and irreversibly to the bond, it means that the first electrode active materials are fixed to each other. do.

The first electrode active material may be a positive electrode active material or a negative electrode active material.

Examples of the positive electrode active material include composite oxides of lithium and transition metals {composite oxides having one type of transition metal (LiCoO ₂ , LiNiO ₂ , LiAlMnO ₄ , LiMnO ₂ , _{LiMn2O 4} , etc.) and transition metal elements. Two types of composite oxides (eg LiFeMnO ₄ , LiNi _1-x Co _x O ₂ , LiMn _1-y Co _y O ₂ , LiNi _1/3 Co _1/3 Al _1/3 O ₂ and LiNi _0.8 Co _0.15 Al _0.05 O ₂ ) and composite oxides containing three or more kinds of metal elements [for example, LiM _a M'b _M''c O ₂ (M, _M'and M'' are different transition metal elements, respectively. And a + b + c = 1. For example, LiNi _1/3 Mn _1/3 Co _1/3 O ₂ ) etc.}, lithium-containing transition metal phosphates (eg LiFePO ₄ , LiCoPO ₄ , LiMnPO ₄ and LiNiPO ₄ ). ), Transition metal oxides (eg MnO ₂ and V ₂ O ₅ ), transition metal sulfides (eg MoS ₂ and TiS ₂ ) and conductive polymers (eg polyaniline, polypyrrole, polythiophene, polyacetylene and poly-p-phenylene and Polyvinylcarbazole) and the like may be mentioned, and two or more kinds may be used in combination.
The lithium-containing transition metal phosphate may be obtained by substituting a part of the transition metal site with another transition metal.

The volume average particle size of the positive electrode active material is preferably 0.01 to 100 μm, more preferably 0.1 to 35 μm, and even more preferably 2 to 30 μm from the viewpoint of the electrical characteristics of the battery. ..

The positive electrode active material may be a coated positive electrode active material in which at least a part of the surface thereof is coated with a coating material containing a polymer compound.
When the periphery of the positive electrode active material is covered with a coating material, the volume change of the positive electrode is alleviated, and the expansion of the positive electrode can be suppressed.

As the polymer compound constituting the coating material, those described as the resin for coating the non-aqueous secondary battery active material in Japanese Patent Application Laid-Open No. 2017-054703 can be preferably used.

The covering material may contain a conductive agent.
As the conductive agent, the same conductive filler as that contained in the first resin current collector can be preferably used.

Examples of the negative electrode active material include carbon-based materials [graphite, non-graphitizable carbon, amorphous carbon, fired resin (for example, those obtained by burning and carbonizing phenol resin and furan resin, etc.), cokes (for example, pitch coke, needle). Coke and petroleum coke, etc.) and carbon fibers], silicon-based materials [silicon, silicon oxide (SiOx), silicon-carbon composite (carbon particles whose surface is coated with silicon and / or silicon carbide, silicon particles or oxidation) The surface of silicon particles coated with carbon and / or silicon carbide, silicon carbide, etc.) and silicon alloys (silicon-aluminum alloy, silicon-lithium alloy, silicon-nickel alloy, silicon-iron alloy, silicon-titanium alloy, silicon) -Manganese alloys, silicon-copper alloys and silicon-tin alloys, etc.)], conductive polymers (eg, polyacetylene and polypyrrole, etc.), metals (tin, aluminum, zirconium, titanium, etc.), metal oxides (titanium oxide and titanium oxide, etc.) Examples thereof include lithium-titanium oxides, etc.), metal alloys (for example, lithium-tin alloys, lithium-aluminum alloys, lithium-aluminum-manganese alloys, etc.) and mixtures of these with carbon-based materials.
Among the above-mentioned negative electrode active materials, those which do not contain lithium or lithium ions inside may be pre-doped with a part or all of the negative electrode active materials containing lithium or lithium ions in advance.

Among these, carbon-based materials, silicon-based materials and mixtures thereof are preferable from the viewpoint of battery capacity and the like, graphite, non-graphitizable carbon and amorphous carbon are more preferable as carbon-based materials, and silicon-based materials are more preferable. , Silicon oxide and silicon-carbon composites are more preferred.

The volume average particle size of the negative electrode active material is preferably 0.01 to 100 μm, more preferably 0.1 to 20 μm, and even more preferably 2 to 10 μm from the viewpoint of the electrical characteristics of the battery.

In the present specification, the volume average particle size of the negative electrode active material means the particle size (Dv50) at an integrated value of 50% in the particle size distribution obtained by the microtrack method (laser diffraction / scattering method). The microtrack method is a method for obtaining a particle size distribution using scattered light obtained by irradiating particles with laser light. A microtrack or the like manufactured by Nikkiso Co., Ltd. can be used for measuring the volume average particle size.

The negative electrode active material may be a coated negative electrode active material in which at least a part of the surface thereof is coated with a coating material containing a polymer compound.
When the periphery of the negative electrode active material is coated with a coating material, the volume change of the negative electrode can be alleviated and the expansion of the negative electrode can be suppressed.

As the coating material, the same material as the coating material constituting the coated positive electrode active material can be preferably used.

The first electrode active material layer may contain an adhesive resin.
The adhesive resin is, for example, a resin in which a small amount of an organic solvent is mixed with the resin for coating a non-aqueous secondary battery active material described in JP-A-2017-054703 and the glass transition temperature is adjusted to room temperature or lower. Further, those described as an adhesive in JP-A No. 10-255805 can be preferably used.
The adhesive resin is a resin having adhesiveness (property of adhering by applying a slight pressure without using water, solvent, heat, etc.) without solidifying even if the solvent component is volatilized and dried. Means. On the other hand, the solution-drying type electrode binder used as a binder means a binder that dries and solidifies by volatilizing a solvent component to firmly bond and fix active substances to each other.
Therefore, the solution-drying type electrode binder (binding material) and the adhesive resin are different materials.

The first electrode active material layer may contain an electrolytic solution containing an electrolyte and a non-aqueous solvent.
As the electrolyte, those used in known electrolytic solutions can be used, for example, lithium salts of inorganic acids such as LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF ₆ , LiN (FSO ₂ ) ₂ and LiClO ₄ . Examples thereof include lithium salts of organic acids such as LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ and LiC (CF ₃ SO ₂ ) ₃ , and LiN (FSO ₂ ) ₂ (also referred to as LiFSI). ) Is preferable.

As the non-aqueous solvent, those used in known electrolytic solutions can be used, for example, lactone compounds, cyclic or chain carbonate esters, chain carboxylic acid esters, cyclic or chain ethers, phosphate esters, nitriles. Compounds, amide compounds, sulfones, sulfolanes and the like and mixtures thereof can be used.

Among the solvents, lactone compounds, cyclic carbonate esters, chain carbonate esters and phosphate esters are preferable from the viewpoint of battery output and charge / discharge cycle characteristics, and lactone compounds, cyclic carbonate esters and chain carbonates are more preferable. Esters, particularly preferred are dimethyl carbonate (SP value: 17.4), 1: 1 (volume ratio) mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) (SP value: 15.9), or. , Ester carbonate (EC) and propylene carbonate (PC) 1: 1 (volume ratio) mixed solution (SP value: 14.1).

The first electrode active material layer may contain a conductive auxiliary agent.
As the conductive auxiliary agent, a conductive material similar to the conductive filler contained in the first resin current collector can be preferably used.

The weight ratio of the conductive auxiliary agent in the first electrode active material layer is preferably 2 to 10% by weight.

The first electrode active material layer is prepared, for example, by applying a slurry containing the first electrode active material and the electrolytic solution to the surface of the first current collector or the base material and removing the excess electrolytic solution. be able to.
When the first electrode active material layer is formed on the surface of the base material, the first electrode active material layer may be combined with the first current collector by a method such as transfer.
The slurry may contain a conductive auxiliary agent or an adhesive resin, if necessary. Further, the electrode active material may be a coated electrode active material.

[Second electrode]
The second electrode includes a second current collector and a second electrode active material layer containing the second electrode active material formed on the second current collector.
The second electrode active material layer preferably contains an electrolytic solution containing an electrolyte.

The second current collector may be a metal current collector made of metal, or may be a resin current collector made of a second matrix resin and a conductive filler (second resin current collector). ..

The thickness of the second current collector is not particularly limited, but is preferably 5 to 150 μm.

As the metal collector, copper, aluminum, titanium, stainless steel, nickel, alloys thereof and the like can be used.

The second resin current collector contains a second matrix resin and a conductive filler.
As the conductive filler, the same conductive filler as that constituting the first resin current collector can be preferably used.
The weight ratio of the conductive filler in the second resin current collector is preferably 5 to 90% by weight, more preferably 20 to 80% by weight.
In particular, when the conductive filler is carbon, the weight ratio of the conductive filler is preferably 20 to 30% by weight.

As the second matrix resin constituting the second resin current collector, the same resin as the first matrix resin constituting the first resin current collector can be used.

The second resin current collector can be obtained, for example, by forming a conductive resin composition obtained by melt-kneading the second matrix resin and the conductive filler into a film shape.
Examples of the method for forming the conductive resin composition into a film include known film forming methods such as a T-die method, an inflation method, and a calendar method. The second resin current collector can also be obtained by a molding method other than film molding.

The second electrode active material layer comprises a second electrode composition containing the second electrode active material.

The second electrode active material is a different type of electrode active material from the first electrode active material.
That is, when the first electrode active material is a positive electrode active material, the second electrode active material is a negative electrode active material, and when the first electrode active material is a negative electrode active material, the second electrode active material is a positive electrode active material. It is a substance.

The second electrode active material layer may contain a conductive auxiliary agent.
As the conductive auxiliary agent, a conductive material similar to the conductive filler constituting the first resin current collector can be preferably used.

The weight ratio of the conductive auxiliary agent in the second electrode active material layer is preferably 2 to 10% by weight.

The second electrode active material layer is prepared, for example, by applying a slurry containing the second electrode active material and the electrolytic solution to the surface of the second current collector or the base material and removing the excess electrolytic solution. be able to.
When the second electrode active material layer is formed on the surface of the base material, the second electrode active material layer may be combined with the second current collector by a method such as transfer.
The slurry may contain a conductive auxiliary agent or an adhesive resin, if necessary. Further, the electrode active material may be a coated electrode active material.

The second electrode active material layer may contain an adhesive resin.
As the adhesive resin, the same adhesive resin as the adhesive resin which is an optional component of the first electrode active material layer can be preferably used.

[Separator]
As the separator, a porous film made of polyethylene or polypropylene, a laminated film of a porous polyethylene film and a porous polypropylene, a non-woven fabric made of synthetic fibers (polyester fiber, aramid fiber, etc.) or glass fiber, etc., and silica on the surface thereof. , Known separators for lithium ion batteries such as those to which ceramic fine particles such as alumina and titania are attached can be mentioned. Of these, the separator is preferably a porous film made of polypropylene.
The melting point of the separator is preferably 200 ° C. or higher.
Further, two or more parators may be arranged on top of each other.

[First sealing material]
The first sealing material adheres the first current collector and the separator.
The first sealing material contains a resin.
The melting point of the resin constituting the first sealing material is preferably less than 200 ° C.
The resin constituting the first sealing material is preferably at least one selected from the group consisting of polyamide, polyvinylidene fluoride and polyolefin.

[Second sealing material]
The second current collector and the separator may be directly adhered to each other, or may be adhered to each other by a second sealing material.
The second sealing material contains a resin.
When the second current collector and the separator are adhered to each other by the second sealing material, the melting point of the resin constituting the second sealing material is 30 ° C. or higher than that of the resin constituting the first sealing material. High is preferable.
When the second current collector and the separator are adhered to each other by the second sealing material, the SP value of the resin constituting the second sealing material and the SP of the resin constituting the first sealing material The absolute value of the difference from the value is preferably more than 3.5.

The resin constituting the second sealing material is preferably at least one selected from the group consisting of polyamide, polyimide, polyvinylidene fluoride, polyester and polyolefin.

[Manufacturing method of solution containing metal ions]
The method for producing a solution containing metal ions of a metal element constituting the electrode active material of the present invention is to use the regenerated electrode active material for a lithium ion battery produced by the method for producing a regenerated electrode active material of the present invention as a solvent containing water. In the dispersion liquid preparation step of obtaining the electrode active material dispersion liquid by dispersing in the electrode active material dispersion, and the electrode active material dispersion so that the hydrogen ion index (pH) of the aqueous solution separated from the electrode active material dispersion liquid is 5 or less at 25 ° C. It is characterized by having a pH adjusting step for adjusting the pH of the liquid.

In the method for producing a solution containing metal ions of a metal element constituting the electrode active material of the present invention, the regenerated electrode active material obtained by the method for producing a regenerated electrode active material of the present invention is dispersed in a solvent containing water. After obtaining the electrode active material dispersion, the pH of the electrode active material dispersion is adjusted to a predetermined value to ionize the metal elements constituting the electrode active material contained in the electrode active material dispersion to ionize the electrode active material. A solution containing metal ions of a metal element constituting a substance (hereinafter, also referred to as a metal ion solution) can be produced.

In the method for producing a recycled electrode active material of the present invention, since the lithium ion battery is not heated at a high temperature of 400 to 550 ° C., the sintered particles of the obtained recycled electrode active material do not proceed, and particles having a large specific surface area can be obtained. .. Therefore, the ion extraction efficiency at the time of acid leaching with an acidic liquid is high, and ion extraction can be performed efficiently.

[Dispersion liquid adjustment process]
In the dispersion liquid adjusting step, the regenerated electrode active material for a lithium ion battery obtained by the method for producing a regenerated electrode active material of the present invention is dispersed in a solvent containing water to obtain an electrode active material dispersion liquid.

The solvent other than water may be a non-polar solvent or a polar solvent. The polar solvent may be a protic polar solvent or an aprotic polar solvent.

Examples of the non-polar solvent include toluene, xylene, hexane, heptane, octane and the like, and two or more kinds may be used in combination.
Examples of the protonic polar solvent include methanol, ethanol and the like, and two or more kinds may be used in combination.
Examples of the aprotic polar solvent include dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), and two or more of them may be used in combination.
The solvent is preferably a mixed solvent of a non-polar solvent and water, or a single solvent of water.
The ratio of water to the mixed solvent of the non-polar solvent and water is preferably 50 to 80% by weight.
The single solvent of water means that only water is used as the solvent.

A water-containing solvent for dispersing the electrode composition is preferably a mixed solvent of water and toluene or a mixed solvent of water and xylene from the viewpoint of metal ion extraction efficiency.

The solid content concentration in the electrode active material dispersion is not particularly limited, but is preferably 50% by weight or less.
If the solid content concentration in the electrode active material dispersion exceeds 50% by weight, the proportion of the solvent in the electrode active material dispersion decreases, and the extraction rate of metal ions after the pH adjustment step decreases. There is.

The electrode active material dispersion liquid may contain a solid component other than the electrode composition.
Examples of solid components other than the electrode composition include current collectors, separators, battery exteriors, and the like. It is desirable that these solid components be separated prior to the pH adjustment step.
Examples of the method for separating solid components include separation using specific gravity, filtration, and centrifugal separation.

[PH adjustment process]
In the pH adjustment step, the pH of the electrode active material dispersion is adjusted so that the hydrogen ion index (pH) at 25 ° C. of the aqueous solution separated from the electrode active material dispersion obtained in the dispersion adjustment step is 5 or less. do. The separated aqueous solution refers to a solution in which a part or all of the electrode active material dispersion liquid is taken out and a solvent other than water is removed.

The pH of the aqueous solution adjusted by the pH adjusting step at 25 ° C. is preferably 3 or more and 5 or less.
Examples of the method for adjusting the pH of the aqueous solution to 5 or less include a method of mixing an electrode active material dispersion and an acid agent.
Examples of the acid agent include sulfuric acid, hydrochloric acid, nitric acid, citric acid, gluconic acid, succinic acid and the like, and two or more of them may be used in combination. Sulfuric acid is preferable as the acid agent.

The pH of the aqueous solution can be measured using a commercially available pH meter.
The method for separating the aqueous solution from the electrode active material dispersion is not particularly limited, and examples thereof include a method in which known separation methods such as filtration, centrifugation, static separation, and adsorption separation are appropriately combined.
At this time, the aqueous solution is separated so as to contain a solute instead of pure water. That is, a method for separating high-purity water from the electrode active material dispersion such as distillation or ion exchange resin is not adopted.

When adjusting the pH of the electrode active material dispersion, an acid agent may be added little by little to the electrode active material dispersion, or the electrode active material dispersion may be added little by little to the acid agent, and the electrode active material is dispersed. The liquid and a predetermined amount of acid agent may be mixed at one time.

The time required for the pH adjustment step is not particularly limited, but is preferably 1 to 3 hours.

The temperature of the electrode active material dispersion liquid in the pH adjusting step is not particularly limited, but is preferably 10 ° C. or higher.

In the pH adjusting step, the electrode active material dispersion may be agitated, or the electrode active material dispersion may be irradiated with ultrasonic waves.

The metal ion solution produced by the method for producing a metal ion solution of the present invention can be used for producing an active material for a lithium ion battery, a catalyst for a chemical reaction, or the like.

Examples of the metal ion contained in the metal ion solution include lithium ion, nickel ion, cobalt ion, manganese ion, iron ion, aluminum ion, vanadium ion, molybdenum ion, titanium ion and the like.

[Lithium-ion battery]
A first embodiment of the lithium ion battery of the present invention comprises a first electrode composition comprising a first current collector and a first electrode active material formed on the first current collector. A second electrode composition comprising a first electrode comprising the electrode active material layer of the above, a second current collector, and a second electrode active material formed on the second current collector. A lithium ion battery including a storage element including a second electrode including the electrode active material layer of the above and a separator arranged between the first electrode active material layer and the second electrode active material layer. The first current collector is adhered to the separator via the first sealing material at the outer peripheral edge portion where the first electrode active material layer is not formed on the collector. The electrode current collector of No. 2 is adhered to the separator via the second sealing material at the outer peripheral edge portion where the second electrode active material layer is not formed on the electrode current collector, and is adhered to the separator. The melting point of the resin constituting the material is less than 200 ° C., and the melting point of the resin constituting the second sealing material is 30 ° C. or more higher than the melting point of the resin constituting the first sealing material. ..

In the first embodiment of the lithium ion battery of the present invention, the melting point of the resin constituting the first sealing material is less than 200 ° C., and the melting point of the resin constituting the second sealing material constitutes the first sealing material. It is higher than the melting point of the resin to be used by 30 ° C. or more.
Therefore, by heating the power storage element at a temperature equal to or higher than the melting point of the resin constituting the first sealing material and lower than 200 ° C., the first sealing material is softened, and the first sealing material is used as a boundary. By separating the current collector of 1 and the separator, the first electrode composition can be selectively taken out.
Therefore, the first embodiment of the lithium ion battery of the present invention is the lithium ion used in the method for producing a recycled electrode active material for a lithium ion battery of the present invention and the method for manufacturing a recycled sheet-shaped electrode member for a lithium ion battery of the present invention. Suitable as a battery.

A second embodiment of the lithium ion battery of the present invention comprises a first electrode composition comprising a first current collector and a first electrode active material formed on the first current collector. A second electrode composition comprising a first electrode comprising the electrode active material layer of the above, a second current collector, and a second electrode active material formed on the second current collector. A lithium ion battery including a storage element including a second electrode including the electrode active material layer of the above and a separator arranged between the first electrode active material layer and the second electrode active material layer. The first current collector is adhered to the separator via the first sealing material at the outer peripheral edge portion where the first electrode active material layer is not formed on the collector. The electrode current collector of No. 2 is adhered to the separator via the second sealing material at the outer peripheral edge portion where the second electrode active material layer is not formed on the electrode current collector, and is adhered to the separator. It is characterized in that the SP value and Tg of the material and the second sealing material satisfy all of the following conditions (1) and (2).
Condition (1): [Absolute value of the difference between the SP value of the resin constituting the first sealing material and the SP value of the resin constituting the second sealing material]> 3.5
Condition (2): [Absolute value of the difference between Tg of the resin constituting the first sealing material and Tg of the resin constituting the second sealing material] ≧ 35

In the second embodiment of the lithium ion battery of the present invention, the SP values and Tg of the first sealing material and the second sealing material satisfy all of the above conditions.
Therefore, the storage element is contained in a solvent in which the difference from the SP value of the resin constituting the first sealing material is less than 1.0 and the difference from the SP value of the resin constituting the second sealing material is more than 2.5. By immersing the first sealant in the solvent, the first sealant is separated from the first current collector and the separator at the boundary of the first sealant, and the first electrode active material layer is selected. Can be taken out.
Therefore, the second embodiment of the lithium ion battery of the present invention is the lithium ion used in the method for manufacturing the recycled electrode active material for a lithium ion battery of the present invention and the method for manufacturing a recycled sheet-shaped electrode member for a lithium ion battery of the present invention. Suitable as a battery.

[Manufacturing method of lithium-ion battery]
In the lithium ion battery of the present invention, for example, a step of preparing a first current collector and a first electrode active material layer containing the first electrode active material are formed on the first current collector. A step of obtaining a first electrode sheet-like member, a step of preparing a second current collector, and a second electrode active material layer containing the second electrode active material are formed on the second current collector. By adhering the first current collector and the separator with the first sealing material in the step of obtaining the second electrode sheet-like member, the first current collector, the separator and the separator are attached. By covering the first electrode active material layer with the sealing material 1 and adhering the second current collector and the separator with the second sealing material, the second current collector and the separator are adhered to each other. It can be produced by the step of covering the second electrode active material layer with the separator and the second sealing material.

The method of adhering the first current collector and the separator with the first sealing material is not particularly limited, but for example, a resin serving as the first sealing material is applied to the edge of the separator to collect the first current. There is a method of adhering to the body. At this time, the first electrode active material layer is sandwiched between the separator and the first current collector.
The same applies to the method of adhering the second current collector and the separator with the second sealing material.

[Manufacturing method of recycled sheet-shaped electrode member for lithium-ion battery]
The method for manufacturing a recycled sheet-shaped electrode member for a lithium ion battery of the present invention is a first electrode composition containing a first current collector and a first electrode active material formed on the first current collector. From a second electrode composition comprising a first electrode comprising a first electrode active material layer, a second current collector, and a second electrode active material formed on the second current collector. A storage element including a second electrode including the second electrode active material layer, and a separator arranged between the first electrode active material layer and the second electrode active material layer. From the lithium ion battery in which the first current collector is adhered to the separator via the first sealing material in the outer peripheral edge portion where the first electrode active material layer is not formed on the collector. A first recycled sheet containing the first current collector and the first electrode active material layer by separating the first current collector and the separator with the first sealing material as a boundary. It is characterized by having a take-out step of taking out a shaped electrode member.

In the method for manufacturing a recycled sheet-shaped electrode member for a lithium ion battery of the present invention, the first current collector and the separator are separated by separating the first current collector and the separator with the first sealing material as a boundary. The first regenerated sheet-like electrode member including the electrode active material layer of 1 is taken out.

In the method for manufacturing a recycled sheet-shaped electrode member for a lithium ion battery of the present invention, the object taken out by the extraction step is not the first electrode active material but the first current collector and the first electrode active material layer. It is the same as the method for producing a recycled electrode active material for a lithium ion battery of the present invention, except that it is the first recycled electrode member including the above.
Therefore, in the method for producing a regenerated electrode active material for a lithium ion battery of the present invention shown in FIGS. 3, 4 and 5, the first current collector 11 and the first electrode active material layer 13 are included. The method for taking out the recycled sheet-shaped electrode member 110 is the method for manufacturing the recycled sheet-shaped electrode member for a lithium ion battery of the present invention.

[Manufacturing method of recycled electrode sheet for lithium ion battery]
The method for producing a regenerated electrode sheet for a lithium ion battery of the present invention comprises a first electrode composition containing a first current collector and a first electrode active material formed on the first current collector. A second electrode composition comprising a first electrode provided with a first electrode active material layer, a second current collector, and a second electrode active material formed on the second current collector. A power storage element including a second electrode provided with two electrode active material layers and a separator arranged between the first electrode active material layer and the second electrode active material layer is provided. The current collector 1 is adhered to the separator via the first sealing material at the outer peripheral edge portion on which the first electrode active material layer is not formed, and the second current collector is bonded to the separator. From the lithium ion battery in which the body is adhered to the separator via the second sealing material at the outer peripheral edge portion on which the second electrode active material layer is not formed, the second sealing material is obtained. The first current collector and the separator are separated from each other, and the first current collector, the first electrode active material layer, the separator, and the first sealing material are formed. It is characterized by having a take-out step of taking out a recycled electrode sheet.

In the method for manufacturing a regenerated electrode sheet for a lithium ion battery of the present invention, the second current collector and the separator are separated from each other with the second sealing material as a boundary. By separating the second current collector and the separator in the power storage element, the first regenerated electrode sheet composed of the first current collector, the first electrode active material layer, the separator and the first sealing material can be obtained. It can be taken out.
In the first regenerated electrode sheet, since the first electrode active material layer is covered with the first current collector, the first sealing material and the separator, the first electrode active material leaks to the outside. There is no. Therefore, it is easy to prevent the mixing of the second electrode active material and the deactivation of the first electrode active material, and it is excellent as a method for recycling or reusing the lithium ion battery in a simple process.

An example of the method for manufacturing the regenerated electrode sheet for a lithium ion battery of the present invention will be described with reference to FIG. 7.
FIG. 7 is a cross-sectional view schematically showing an example of a take-out process in the method for manufacturing a recycled electrode sheet for a lithium ion battery of the present invention.
In FIG. 7, the second current collector 21 and the separator 30 are separated from each other with the second sealing material 25 constituting the power storage element 40 as a boundary. By separating the second current collector 21 and the separator 30 with the second sealing material 25 as a boundary, the first current collector 11, the first electrode active material layer 13, and the first sealing material are separated. A first regenerated electrode sheet 120 composed of 15 and a separator 30 can be obtained.

As a method for separating the second current collector and the separator with the second sheet member as a boundary, the first sealing material is used as a boundary in the method for producing a regenerated electrode active material for a lithium ion battery of the present invention. A method of applying the method of separating the first current collector and the separator to the second sealing material can be mentioned.
That is, as a method of separating the second current collector and the separator with the second sealing material as a boundary, a method of heating the power storage element, a method of immersing the power storage element in a solvent, and a second seal. Examples include a method of cutting the material.

When the power storage element is heated in the take-out step, the take-out step heats the power storage element at a temperature equal to or higher than the melting point of the resin constituting the second sealing material and lower than the melting point of the resin constituting the first sealing material. It is preferable to have.

When the power storage element is immersed in the solvent in the extraction step, the extraction step includes a step of immersing the storage element in the solvent, and the absolute difference between the SP value of the resin constituting the second sealing material and the SP value of the solvent is absolute. It is preferable that the value is 1.0 or less and the absolute value of the difference between the SP value of the resin constituting the first sealing material and the SP value of the solvent exceeds 2.5.

When cutting the second sealing material in the taking-out step, the taking-out step includes a step of cutting the second sealing material along a direction substantially perpendicular to the direction in which the second current collector and the separator face each other. Is preferable.

The regenerated electrode sheet for a lithium ion battery produced by the method for producing a regenerated electrode sheet for a lithium ion battery of the present invention may be used again in the production of a lithium ion battery in combination with an electrode sheet having a different polarity.

In the method for producing a regenerated electrode sheet for a lithium ion battery of the present invention, it is preferable to carry out the extraction step under the condition that the first electrode active material is not deactivated.
If the first electrode active material is deactivated, it becomes difficult to reuse the regenerated electrode sheet for a lithium ion battery obtained by the method for producing a regenerated electrode sheet for a lithium ion battery of the present invention.

In order not to inactivate the first electrode active material, it is preferable not to bring the first electrode active material into contact with water. Further, the atmosphere in which the extraction process is performed is preferably in a dry room environment with a dew point of −30 ° C. or lower.

The regenerated electrode sheet obtained by the method for manufacturing a regenerated electrode sheet for a lithium ion battery of the present invention has a configuration corresponding to a half battery of a lithium ion battery, which is a first current collector, a first electrode active material layer and a separator. Therefore, a new lithium-ion battery can be manufactured by combining with electrodes having different polarities.

The configuration of the lithium ion battery used in the method for manufacturing the regenerated electrode sheet for a lithium ion battery of the present invention is the case where the power storage element is heated in the take-out step and the case where the power storage element is immersed in a solvent in the take-out step. From the lithium ion battery used in the method for manufacturing the recycled electrode active material for a lithium ion battery of the present invention and the lithium ion battery used in the method for manufacturing a recycled sheet-shaped electrode member for a lithium ion battery of the present invention, the first electrode and It is preferable that the configuration of the second electrode is reversed.
On the other hand, when the second sealing material is cut in the taking-out step, the lithium ion battery used in the method for manufacturing the recycled electrode active material for a lithium ion battery of the present invention and the recycled sheet-shaped electrode member for a lithium ion battery of the present invention are manufactured. It is preferable that the configuration is similar to that of the lithium ion battery used in the method.

Next, the present invention will be specifically described with reference to Examples, but the present invention is not limited to the Examples as long as it does not deviate from the gist of the present invention. Unless otherwise specified, parts mean parts by weight and% means parts by weight. In the following examples, the first electrode is a positive electrode.

[Manufacturing Example 1]
<Manufacturing of resin current collector>
Using a twin-screw extruder, 190 parts of resin [TPX (polymethylpentene) manufactured by Mitsui Chemicals, Inc., melting point 235 ° C], 30 parts of [Denka Black Li-400 manufactured by Denka Co., Ltd.] and 5 parts of dispersant. A material for a resin current collector was obtained by melt-kneading at a temperature of 100 rpm and a residence time of 5 minutes.
The obtained resin collector material was extruded from a T-die and rolled with a cooling roll whose temperature was adjusted to 50 ° C. to obtain a resin collector having a film thickness of 100 μm.

[Manufacturing Example 2]
[Preparation of coated positive electrode active material]
70.0 parts of DMF was placed in a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, and the temperature was raised to 75 ° C. Next, a monomer compounding solution containing 20.0 parts of butyl methacrylate, 55.0 parts of acrylic acid, 22.0 parts of methyl methacrylate, 3 parts of sodium allylsulfonate and 20 parts of DMF, and 2,2'-azobis (2). , 4-Dimethylvaleronitrile) 0.4 part and 2,2'-azobis (2-methylbutyronitrile) 0.8 part dissolved in 10.0 parts of DMF Initiator solution and nitrogen in a 4-mouth flask. Radical polymerization was carried out by continuously dropping the solution with a dropping funnel over 2 hours while stirring. After completion of the dropping, the temperature was raised to 80 ° C. and the reaction was continued for 5 hours to obtain a copolymer solution having a resin concentration of 50% by weight. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a polymer compound for coating.
Subsequently, 100 parts of the positive electrode active material powder (LiNi _0.8 Co _0.15 Al _0.05 O ₂ powder, volume average particle diameter 4 μm) was placed in the universal mixer high-speed mixer FS25 [manufactured by Arstecnica Co., Ltd.]. In a state of stirring at room temperature and 720 rpm, 11.2 parts of the polymer compound solution for coating obtained by dissolving the polymer compound for coating in isopropanol at a concentration of 1.0% by weight was added dropwise over 2 minutes. , Further stirred for 5 minutes.
Then, in a stirred state, 6.2 parts of acetylene black [Denka Black (registered trademark) manufactured by Denka Co., Ltd.] was added as a conductive agent in 2 minutes while being divided, and stirring was continued for 30 minutes. Then, the pressure was reduced to 0.01 MPa while maintaining the stirring, then the temperature was raised to 140 ° C. while maintaining the stirring and the degree of decompression, and the stirring, the degree of decompression and the temperature were maintained for 8 hours to distill off the volatile components. .. The obtained powder was classified with a sieve having an opening of 212 μm to obtain a coated positive electrode active material.

[Manufacturing Example 3]
<Manufacturing of coated negative electrode active material>
100 parts of non-graphitizable carbon powder (volume average particle diameter 20 μm), which is a carbon-based material, was placed in a universal mixer high-speed mixer FS25 [manufactured by Arstecnica Co., Ltd.] and stirred at room temperature at 720 rpm. 9.2 parts of the polymer compound solution for coating obtained by dissolving the polymer compound for coating in isopropanol at a concentration of 19.8% by weight was added dropwise over 2 minutes, and the mixture was further stirred for 5 minutes.
Then, while stirring, 11.3 parts of acetylene black [Denka Black (registered trademark) manufactured by Denka Co., Ltd.], which is a conductive agent, was added in 2 minutes while being divided, and stirring was continued for 30 minutes. Then, the pressure was reduced to 0.01 MPa while maintaining the stirring, then the temperature was raised to 140 ° C. while maintaining the stirring and the degree of decompression, and the stirring, the degree of decompression and the temperature were maintained for 8 hours to distill off the volatile components. .. The obtained powder was classified with a sieve having an opening of 212 μm to obtain a coated negative electrode active material.

<Example 1>
<Making the first electrode (positive electrode)>
42 parts of an electrolytic solution prepared by dissolving LiN (FSO ₂ ) ₂ at a ratio of 2 mol / L in a mixed solvent (volume ratio 1: 1) of ethylene carbonate (EC) and propylene carbonate (PC) and carbon fiber [Osaka Gas] Donna Carbo Mild S-243 manufactured by Chemical Co., Ltd.] 4.2 parts were mixed with a planetary stirring type mixing and kneading device {Awatori Kentarou [Shinky Co., Ltd.]} at 2000 rpm for 7 minutes, and then the above. After adding 30 parts of the electrolytic solution and 206 parts of the coated positive electrode active material, the mixture is further mixed at 2000 rpm for 1.5 minutes by Rentaro Awatori, and after 20 parts of the electrolytic solution is further added, stirring by Rentaro Awatori is performed at 2000 rpm. After adding 2.3 parts of the above electrolyte solution for 1 minute, stirring with Awatori Rentaro was mixed at 2000 rpm for 1.5 minutes to prepare a positive electrode active material slurry.
The obtained positive electrode active material slurry was applied to the surface of the resin current collector obtained in Production Example 1 as the first current collector, pressed at a pressure of 5 MPa for about 10 seconds, and the lithium ion according to Example 1 was applied. A sheet-shaped positive electrode member (42 mm × 42 mm) for a battery was produced. In the sheet-shaped positive electrode member for a lithium ion battery according to the first embodiment, a positive electrode active material layer having a plan view dimension of 35 mm × 35 mm is provided substantially in the center of a first current collector having a plan view dimension of 42 mm × 42 mm. Have been placed.

<Adhesion of the first current collector and separator with the first sealing material>
Adhesive polyolefin film [Admer manufactured by Mitsui Kagaku Co., Ltd.] cut out to a width of 2 mm on the outer edge of a flat plate-shaped cell guard 3501 [PP (melting point: 160 ° C), thickness 25 μm, plan view size 42 mm × 42 mm] to be a separator. (Registered trademark) VE300 melting point 90 ° C. thickness 50 μm] was arranged and superposed on the positive electrode active material layer of the positive electrode sheet-like member for a lithium ion battery according to Example 1 to bond the first current collector and the separator. ..

<Manufacturing of the second electrode (negative electrode)>
20 parts of an electrolytic solution prepared by dissolving LiN (FSO ₂ ) ₂ at a ratio of 2 mol / L in a mixed solvent (volume ratio 1: 1) of ethylene carbonate (EC) and propylene carbonate (PC) and carbon fiber [Osaka Gas] Chemical Co., Ltd. Donna Carbo Mild S-243] 2 parts are mixed with a planetary stirring type mixing and kneading device {Awatori Kentarou [Sinky Co., Ltd.]} at 2000 rpm for 7 minutes, and then the above electrolyte solution. After adding 50 parts and 98 parts of the coated negative electrode active material, mix with Awatori Rentaro at 2000 rpm for 1.5 minutes, add 25 parts of the electrolyte solution, and then stir with Awatori Rentaro at 2000 rpm for 1 part. After that, 50 parts of the above electrolytic solution was further added, and then stirring by Awatori Rentaro was mixed at 2000 rpm for 1.5 minutes to prepare a negative electrode active material slurry.

<Adhesion of the second current collector and separator with the second sealing material>
The obtained negative electrode active material slurry was applied to the surface of the aramid separator and pressed at a pressure of 5 MPa for 10 seconds to form a negative electrode active material layer on the separator.
After transferring this negative electrode active material layer to a surface that is not in contact with the positive electrode active material layer of the separator, a high molecular weight saturated copolymer polyester with a width of 2 mm is applied to the outer edge of the separator [Nichigo Polyester manufactured by Nippon Synthetic Chemical Co., Ltd. (Nichigo Polyester). After applying a toluene solution of (registered trademark) SP-181 melting point 140 ° C.] to remove the solvent, the second collector is superposed on the resin collector obtained in Production Example 1 to be the second collector. The electric body and the separator were adhered and sealed in an aluminum laminated film to obtain a lithium ion battery according to Example 1.
The plan view dimension of the negative electrode active material layer is a square having a size of 35 mm × 35 mm.

<Confirmation of take-out property of the first regenerated electrode active material>
The power storage element from which the aluminum laminate film was removed from the lithium ion battery according to Example 1 was placed in a solvent (propylene carbonate) heated to a temperature (120 ° C.) 30 ° C. higher than the melting point of the resin constituting the first sealing material. It was immersed for 10 minutes while applying vibration.
By immersing while applying vibration, the first sealing material swells and softens, and the first current collector and the separator are separated at the boundary of the first sealing material, and the first electrode active material is released. A dispersion liquid dispersed in a solvent was obtained.
Those for which the first electrode active material could be taken out were evaluated as "○". The results are shown in Table 1.

[Evaluation of selectivity]
It is confirmed whether or not the coated negative electrode active material is contained in the above dispersion, the one that does not contain the coated negative electrode active material is evaluated as "○", and the one that contains the coated negative electrode active material is "×". I evaluated it. The results are shown in Table 1.

<Examples 2 to 4>
The lithium ion batteries according to Examples 2 to 4 were produced in the same procedure as in Example 1 except that the types of the first sealing material and the second sealing material were changed as shown in Table 1. Then, the first electrode active material was taken out and the selectivity was evaluated. However, the temperature of the solvent was set to the melting point of the resin constituting the first sealing material + 30 ° C. The results are shown in Table 1.
The types of resins shown in Table 1 are as follows.
A: Mitsui Chemicals, Inc. Admer (registered trademark) VE300 (adhesive polyolefin melting point 90 ° C)
B: Nichigo Polyester (registered trademark) SP-181 (high molecular weight saturated copolymer polyester melting point 140 ° C) manufactured by Nippon Synthetic Chemical Co., Ltd.
C: Modic (registered trademark) F502 (adhesive polyolefin melting point 70 ° C) manufactured by Mitsubishi Chemical Corporation

<Example 5>
A lithium ion battery according to Example 5 having the same first sealing material and second sealing material as in Example 2 was produced.
The aluminum laminated film is removed from the lithium-ion battery to take out the power storage element, and the first sealing material existing on the outer peripheral edge portion is provided along a direction substantially perpendicular to the direction in which the first current collector and the separator face each other. The first sealing material was divided into substantially two equal parts in the direction in which the first current collector and the separator face each other. A first recycled sheet in which a first electrode active material layer is formed on the first current collector by separating the first current collector and the separator with the first sealing material as a boundary. An electrode member was obtained.
Further, the first electrode active material, which is the regenerated electrode active material, was obtained by scraping the first electrode active material from the first recycled sheet-shaped electrode member using a squeegee and collecting it in a glass container. ..
It was confirmed that the second electrode active material was not contained in the first electrode active material.

<Example 6>
A lithium ion battery according to Example 6 having the same first sealing material and second sealing material as in Example 2 was produced. By removing the aluminum laminate film from the lithium ion battery, taking out the power storage element, and cutting the second sealing material existing in the outer peripheral edge portion, the second current collector is separated from the second sealing material. And the separator were separated. Since the second electrode active material layer is formed on the second current collector, the power storage element has the second current collector and the second electrode active material layer as a boundary with the second sealing material as a boundary. It was separated into a second regenerated electrode member made of a regenerated sheet and a first regenerated electrode sheet made of a first current collector, a first electrode active material, a separator and a first sealing material.
In Example 6, each step of removing the aluminum laminated film, cutting the second sealing material, and the like was performed in a dry room environment with a dew point of −30 ° C. or lower.
Further, the first regenerated electrode sheet is disassembled to take out the first electrode active material so that the second electrode active material is not mixed, and the first electrode active material is deactivated by water. I confirmed that there was no such thing.

From the results shown in Table 1, in the method for producing a regenerated electrode active material for a lithium ion battery of the present invention, a positive electrode active material which is a regenerated electrode active material could be obtained by a simple process without requiring high temperature heating.
Further, from the results of Examples 1 and 2, when the melting point of the resin constituting the second sealing material is higher than the melting point of the resin constituting the first sealing material by 30 ° C. or more, the negative electrode active material is mixed. It was confirmed that the positive electrode active material could be obtained in a non-existent state and the selectivity was good.
Further, from the results of Example 5, by separating the first current collector and the separator with the first sealing material as a boundary, the positive electrode active material can be obtained in a state where the negative electrode active material is not mixed. , It was confirmed that the selectivity was good. Further, from the results of Example 5, the lithium ion battery of the present invention is suitable for the method for producing a recycled electrode active material for a lithium ion battery of the present invention and the method for manufacturing a recycled sheet-shaped electrode member for a lithium ion battery of the present invention. I understood it.
Further, from the results of Example 6, the first positive electrode active material containing the first positive electrode active material which is not mixed with the second electrode active material and is not deactivated by water by cutting the second sealing material. It was confirmed that the regenerated electrode sheet of the above can be obtained. Further, from the results of Example 6, when the method for producing a regenerated electrode sheet for a lithium ion battery of the present invention is used, a regenerated electrode sheet for a lithium ion battery can be produced without deactivating the first electrode active material. I found that I could do it.
It was found that the lithium ion battery of the present invention is suitable for the method for producing a regenerated electrode active material for a lithium ion battery of the present invention.

The method for producing a regenerated electrode active material for a lithium ion battery of the present invention is useful as a method for recovering an electrode active material from a lithium ion battery.
The method for producing a metal ion solution of the present invention is useful as a method for recycling valuable metals contained in a lithium ion battery.
The lithium ion battery of the present invention is particularly useful as a lithium ion battery used for mobile phones, personal computers, hybrid vehicles and electric vehicles.
The method for manufacturing a recycled sheet-shaped electrode member for a lithium ion battery of the present invention is useful as a method for recovering an electrode active material from a lithium ion battery.
The method for manufacturing a regenerated electrode sheet for a lithium ion battery of the present invention is useful as a method for taking out an electrode active material from a lithium ion battery and reusing it.

1 Lithium ion battery 10 1st electrode 11 1st current collector 13 1st electrode active material layer 14 Regenerated electrode active material 15 1st sealing material 20 2nd electrode 21 2nd current collector 23 2nd Electrode active material layer 25 Second sealing material 30 Separator 40 Power storage element 50 Battery exterior 60 Solvent 90 Squeegee 110 Recycled sheet-shaped electrode member 120 Regenerated electrode sheet

Claims (5)

A first electrode comprising a first electrode active material layer comprising a first electrode composition including a first current collector and a first electrode active material formed on the first current collector, the first electrode. A second electrode having a second electrode active material layer composed of a second electrode composition containing the second current collector and the second electrode active material formed on the second current collector, and a second electrode. A power storage element including a separator arranged between the first electrode active material layer and the second electrode active material layer is provided.
The first current collector is the first resin current collector, and the first current collector is the first in the outer peripheral edge portion where the first electrode active material layer is not formed on the first collector. From the lithium-ion battery that is adhered to the separator via the sealing material of
Regeneration for a lithium ion battery, comprising a take-out step of separating the first current collector and the separator with the first sealing material as a boundary to take out the first electrode active material. Method for manufacturing electrode active material. The regenerated electrode active material for a lithium ion battery according to claim 1, wherein the taking-out step comprises a step of heating the power storage element at a temperature equal to or higher than the melting point of the resin constituting the first sealing material and lower than 200 ° C. Production method. The extraction step includes a step of immersing the power storage element in a solvent, and the absolute value of the difference between the SP value of the resin constituting the first sealing material and the SP value of the solvent is 1.0 or less. The method for producing a regenerated electrode active material for a lithium ion battery according to claim 1. The lithium ion battery according to claim 1, wherein the extraction step comprises a step of cutting the first sealing material along a direction substantially perpendicular to the direction in which the first current collector and the separator face each other. A method for manufacturing a recycled electrode active material for use. Preparation of a dispersion liquid obtained by dispersing the regenerated electrode active material obtained by the method for producing a regenerated electrode active material for a lithium ion battery according to any one of claims 1 to 4 in a solvent containing water to obtain an electrode active material dispersion liquid. Process and
It comprises an electrode active material having a pH adjusting step of adjusting the pH of the electrode active material dispersion so that the hydrogen ion index (pH) of the aqueous solution separated from the electrode active material dispersion at 25 ° C. is 5 or less. A method for producing a solution containing metal ions of a metal element.

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