JP2022147471A - Material collecting method for bipolar storage battery - Google Patents

Abstract

A material recovery method capable of easily recovering a metal material from a bipolar electrode of a bipolar storage battery is provided. A bipolar lead-acid battery (1) includes a bipolar electrode (130) having a positive electrode (120) formed on one surface of a resin substrate (111) and a negative electrode (110) formed on the other surface. The positive electrode 120 and the negative electrode 110 include current collectors 101 and 102 made of a metal material and adhered to a substrate 111 via a resin adhesive 106 . A material recovery method for the bipolar lead-acid battery 1 includes a dismantling step of dismantling the bipolar lead-acid battery 1 to separate the bipolar electrode 130, and separating the bipolar electrode 130 from one or both of the substrate 111 and the adhesive 106 by softening, melting, Alternatively, a resin removal step of removing one or both of the substrate 111 and the adhesive 106 from the bipolar electrode 130 by heating to a temperature above the thermal decomposition temperature and below the melting point of the metal material forming the current collectors 101 and 102; have [Selection drawing] Fig. 1

Description

The present invention relates to a material recovery method for bipolar storage batteries.

Conventionally, in storage batteries such as lead-acid batteries, metal materials are recovered and recycled after use. For example, in the case of a lead-acid battery, current collectors made of lead are recovered from the positive and negative electrodes. In a typical lead-acid battery, the positive and negative electrodes are mainly composed of current collectors and active materials. By separating the negative electrode, the current collector could be easily recovered.

However, in the case of a bipolar lead-acid battery, current collectors made of lead foil are firmly bonded to both sides of a substrate made of resin or the like to form a bipolar electrode. Recovering the current collector from the bipolar electrode was not easy. Therefore, in the case of the bipolar lead-acid battery, the current collector cannot be collected by an easy method as in the general lead-acid battery described above.

JP-A-60-172180

An object of the present invention is to provide a material recovery method capable of easily recovering a metal material from a bipolar electrode of a bipolar storage battery.

A material recovery method for a bipolar storage battery according to one aspect of the present invention includes a bipolar electrode in which a positive electrode is formed on one surface of a resin substrate and a negative electrode is formed on the other surface of the substrate, and the positive electrode is made of a metal material. and a current collector adhered to one surface of the substrate via a resin adhesive; and a positive electrode active material disposed on the current collector, wherein the negative electrode is made of a metal material and A material recovery method for a bipolar storage battery comprising a current collector adhered to the other surface of a substrate via a resin adhesive and a negative electrode active material disposed on the current collector, comprising: a dismantling step of dismantling the bipolar storage battery to separate the bipolar electrodes; and a resin removal step of removing one or both of the substrate and the adhesive from the bipolar electrode by heating to below the melting point of the metal material forming the current collector.

The material recovery method for a bipolar storage battery according to the present invention is a temperature at which one or both of the substrate and the adhesive soften, melt, or thermally decompose, and below the melting point of the metal material forming the current collectors of the positive and negative electrodes. Since the bipolar electrode is heated to a high temperature to remove one or both of the substrate and the adhesive from the bipolar electrode, the metal material can be easily recovered from the bipolar electrode of the bipolar storage battery.

It is a sectional view explaining the structure of a bipolar lead-acid battery.

An embodiment of the present invention will be described. In addition, the embodiment described below shows an example of the present invention. In addition, various changes or improvements can be added to the present embodiment, and forms to which such changes or improvements are added can also be included in the present invention.

First, referring to FIG. 1, the structure of a bipolar lead-acid battery 1, which is an example of a bipolar-type storage battery to which the bipolar-type storage battery material recovery method according to the present embodiment can be applied, will be described. The bipolar lead-acid battery 1 shown in FIG. A unit and a bipolar electrode 130 having a positive electrode 120 formed on one surface and a negative electrode 110 formed on the other surface of a substrate 111 made of thermoplastic resin are fixed inside a frame plate-like third plate 13 . It has a plate unit and a fourth plate unit in which the positive electrode 120 is fixed to the flat fourth plate 14 .

By alternately stacking the second plate unit and the third plate unit between the first plate unit and the fourth plate unit, the bipolar lead-acid battery 1 having a substantially rectangular parallelepiped shape is configured. The numbers of the stacked second plate units and third plate units are set so that the storage capacity of the bipolar lead-acid battery 1 is a desired value.

A negative electrode terminal 107 is fixed to the first plate 11 , and the negative electrode 110 fixed to the first plate 11 and the negative electrode terminal 107 are electrically connected.
A positive electrode terminal 108 is fixed to the fourth plate 14 , and the positive electrode 120 fixed to the fourth plate 14 and the positive electrode terminal 108 are electrically connected.

The electrolytic layer 105 is composed of, for example, a glass fiber mat impregnated with an electrolytic solution containing sulfuric acid.
The first to fourth plates 11, 12, 13, 14 are made of, for example, well-known molding resin. The first to fourth plates 11, 12, 13, and 14 are fixed to each other by an appropriate method so that the inside is sealed so that the electrolyte does not flow out.

The positive electrode 120 includes a current collector 101 made of lead or a lead alloy and adhered to the one surface of the substrate 111 via a resin adhesive 106 , and a positive electrode active material disposed on the current collector 101 . a substance 103; That is, on the one surface of the substrate 111, the adhesive 106, the current collector 101, and the positive electrode active material 103 are laminated in this order. The above lead or lead alloy is a metal material that is a constituent element of the present invention, and in the present embodiment, the current collector 101 is made of lead or lead alloy foil.

The negative electrode 110 includes a current collector 102 made of lead or a lead alloy and bonded to the other surface of the substrate 111 via a resin adhesive 106 , and a negative electrode active layer disposed on the current collector 102 . a substance 104; That is, on the other surface of the substrate 111, the adhesive 106, the current collector 102, and the negative electrode active material 104 are laminated in this order. The above-described lead or lead alloy is a metal material that is a constituent element of the present invention, and in the present embodiment, the current collector 102 is made of foil made of lead or a lead alloy.
These positive electrodes 120 and negative electrodes 110 are electrically connected by an appropriate method.

In the bipolar lead-acid battery 1 of this embodiment having such a configuration, as described above, the substrate 111, the current collector 101 of the positive electrode 120, the active material 103 for the positive electrode, the current collector 102 of the negative electrode 110, and the negative electrode A bipolar electrode 130 is configured by the active material 104 . A bipolar electrode is a single electrode that functions as both a positive electrode and a negative electrode.
In the bipolar lead-acid battery 1 of the present embodiment, a plurality of cell members each having an electrolytic layer 105 interposed between the positive electrode 120 and the negative electrode 110 are alternately laminated and assembled, thereby connecting the cell members in series. It has a battery configuration that

Examples of the thermoplastic resin forming the substrate 111 include acrylonitrile-butadiene-styrene copolymer (ABS resin, melting point 100 to 125°C), polypropylene (melting point 168°C), polystyrene (melting point 240°C, glass transition point 100°C). ), acrylonitrile styrene copolymer (AS resin, melting point 115°C), polyethylene (melting point 95-140°C), polyvinyl chloride (melting point 85-210°C), acrylic resin (melting point 90-105°C), nylon 6 (melting point 225° C.), polycarbonate (melting point 150° C.), polyvinylidene chloride (melting point 210° C.), and polyvinylidene fluoride (melting point 134-169° C.).

These thermoplastic resins have excellent moldability and excellent sulfuric acid resistance. Therefore, even if the electrolytic solution comes into contact with the substrate 111, the substrate 111 is unlikely to be decomposed, deteriorated, corroded, or the like. It should be noted that the substrate 111 may be made of any resin as long as it is made of a thermosetting resin instead of a thermoplastic resin.

Examples of thermosetting resins include phenol resin (thermal decomposition temperature of 150°C or higher), melamine resin (thermal decomposition temperature of 110°C or higher), urethane resin (thermal decomposition temperature of 90°C or higher), silicone resin (thermal decomposition temperature of 200°C or higher). above), urea resin (thermal decomposition temperature of 90° C. or higher), epoxy resin (thermal decomposition temperature of 150° C. or higher), and furan resin (thermal decomposition temperature of 200° C. or higher).

In addition, as the resin adhesive 106, a general one can be used without any problem. For example, a hot melt adhesive made of a thermoplastic resin or a cured product obtained by curing a reactive curing adhesive can be used. can be done. Examples of reaction-curable adhesives include adhesives containing the above thermosetting resins. These thermosetting resins may be used alone or in combination of two or more.

Examples of reaction-curable adhesives containing epoxy resins include adhesives of the type in which a main agent containing an epoxy resin is mixed with a curing agent containing an amine compound, and the main agent and the curing agent are allowed to react to cure. be done. Since such a reaction-curing adhesive can be cured at room temperature (for example, 20° C. or higher and 40° C. or lower), lead or lead forming the current collector 101 of the positive electrode 120 and the current collector 102 of the negative electrode 110 It can be hardened at a temperature that does not easily affect the metallographic structure of the lead alloy. Furthermore, the reaction-curing adhesive hardly adversely affects the resin forming the substrate 111 . Furthermore, the reaction-curing adhesive has advantages such as high adhesiveness and long usable life.

Examples of the epoxy resin contained in the main agent include at least one of a bisphenol A type epoxy resin and a bisphenol F type epoxy resin. An epoxy resin may be used individually by 1 type, and may use 2 or more types together.
Amine compounds contained in the curing agent include, for example, aliphatic polyamine compounds, alicyclic polyamine compounds, and aromatic polyamine compounds. These amine compounds may be used individually by 1 type, and may use 2 or more types together.

Specific examples of the aliphatic polyamine compound include aliphatic primary amines such as _{triethylenetetramine ( C6H18N4} ) and aliphatic secondary amines such as triethylenetetramine. Specific examples of alicyclic polyamine compounds include alicyclic primary amines such as _{isophoronediamine ( C10H22N2} ). Specific examples of aromatic polyamine compounds include aromatic primary amines such as _{diaminodiphenylmethane ( C13H14N2} ).

Furthermore, in the present embodiment, the bipolar lead-acid battery was exemplified as an example of the bipolar storage battery, but the present invention can be applied to a bipolar lithium ion storage battery or the like other than the bipolar lead-acid battery. In the case of a bipolar lithium ion storage battery, the metallic material forming the current collector is for example copper.
In addition to the above, metal materials for forming the current collector include aluminum, silver, gold, platinum, titanium, nickel, rhodium, and the like. Also, an alloy containing these metals as a main component may be used as the metal material forming the current collector. These metal materials may be used individually by 1 type, and may use 2 or more types together.

Next, a method for recovering materials from the bipolar lead-acid battery as described above by the method for recovering material for the bipolar storage battery according to the present embodiment will be described.
First, the bipolar lead-acid battery 1 is disassembled to separate the bipolar electrodes 130 (disassembly step). Then, the bipolar electrode 130 obtained in the dismantling process is heated to remove one or both of the substrate 111 and the adhesive 106 from the bipolar electrode 130 (resin removing process).

In this resin removal process, the temperature at which one or both of the substrate 111 and the adhesive 106 are softened, melted, or thermally decomposed or higher and the melting point of the metal material forming the current collectors 101 and 102 of the positive electrode 120 and the negative electrode 110 Heat the bipolar electrode 130 to less than If one or both of the substrate 111 and the adhesive 106 are softened, melted, or pyrolyzed by heating, the softened, melted, or pyrolyzed one of the substrate 111 and the adhesive 106 is easily removed from the bipolar electrode 130. be able to. Therefore, the current collectors 101 and 102 can be separated from the bipolar electrode 130 , so that the metal material can be easily recovered from the bipolar electrode 130 .

When the resin forming the substrate 111 and the adhesive 106 is a thermoplastic resin and a crystalline resin, if the bipolar electrode 130 is heated above the melting point of the resin, the substrate 111 and the adhesive 106 will melt and flow. Therefore, the substrate 111 and the adhesive 106 can be easily removed from the bipolar electrode 130 . Further, if bipolar electrode 130 is heated to a temperature higher than the thermal decomposition temperature of the resin, substrate 111 and adhesive 106 are thermally decomposed, so substrate 111 and adhesive 106 can be easily removed from bipolar electrode 130 .

Further, when the resin forming the substrate 111 and the adhesive 106 is a thermoplastic resin and an amorphous resin, if the bipolar electrode 130 is heated above the softening temperature (for example, the glass transition point) of the resin, Since the substrate 111 and the adhesive 106 are softened and fluidized, the substrate 111 and the adhesive 106 can be easily removed from the bipolar electrode 130 . Further, if bipolar electrode 130 is heated to a temperature higher than the thermal decomposition temperature of the resin, substrate 111 and adhesive 106 are thermally decomposed, so substrate 111 and adhesive 106 can be easily removed from bipolar electrode 130 .

Furthermore, if the resin forming the substrate 111 and the adhesive 106 is a thermosetting resin, the substrate 111 and the adhesive 106 will be thermally decomposed if the bipolar electrode 130 is heated above the thermal decomposition temperature of the resin. , the substrate 111 and the adhesive 106 can be easily removed from the bipolar electrode 130 .

Examples of the heating method of the bipolar electrode 130 in the resin removal step include a method of storing the bipolar electrode 130 in a heating device such as an oven and heating the bipolar electrode 130, a heating method by electromagnetic induction heating, a heating method by infrared irradiation, and a high-temperature heat medium. is brought into contact with the bipolar electrode 130, and the like.

A heating method using electromagnetic induction heating is a method of generating Joule heat by eddy currents generated in current collectors 101 and 102 by electromagnetic induction, and heating bipolar electrode 130 with this Joule heat.
The heat medium used in the heating method in which the high-temperature heat medium is brought into contact with the bipolar electrodes 130 may be gaseous, liquid, or solid.

A gaseous heat medium includes a high-temperature gas. Examples include hot air, nitrogen gas, carbon monoxide, carbon dioxide, helium, and argon. Examples of the heating method using a gaseous heat medium include a method of placing the bipolar electrodes 130 in a gaseous heat medium and a method of spraying the gaseous heat medium onto the bipolar electrodes 130 .

As the liquid heat medium, a high boiling point solvent heated to a high temperature can be used. Specific examples of high boiling point solvents include alcohols such as benzyl alcohol (boiling point 205°C), diethylene glycol (boiling point 245°C), hexanol (boiling point 157°C), ketone solvents such as acetophenone (boiling point 202°C), and biphenyl ( aromatic hydrocarbons such as diphenyl ether (boiling point 258°C), acetic acid (boiling point 118°C), acetic anhydride (boiling point 140°C), ethyl acetoacetate (boiling point 180°C), etc. Ester solvents, N-methyl-2-pyrrolidone (boiling point 202 ° C.), amide solvents such as formamide (boiling point 210 ° C.), amine solvents such as aniline (boiling point 184 ° C.), and various oils. .

Examples of oils include olive oil (smoke temperature 200°C), peanut oil (smoke temperature 230°C), coconut oil (smoke temperature 175°C), grapeseed oil (smoke temperature 200°C), sunflower oil (smoke temperature 230°C). ), corn oil (smoke temperature 240° C.), and silicone oil (smoke temperature 250-300° C.).
The type of liquid heat medium depends on the softening temperature, melting point, and thermal decomposition temperature of the resin forming the substrate 111 and the resin forming the adhesive 106, and the melting points of the metal materials forming the current collectors 101 and 102. Therefore, one having a suitable boiling point and smoking temperature may be selected.

If a liquid heat medium heated to a high temperature under pressure is brought into contact with the bipolar electrodes 130, it can be used as the liquid heat medium even if it is not a high boiling point solvent. For example, water has a boiling point of over 100° C. under pressure of over 1 atm, so liquid water of over 100° C. can be obtained under pressure. Therefore, a suitable boiling point is obtained depending on the softening temperature, melting point, and thermal decomposition temperature of the resin forming the substrate 111 and the resin forming the adhesive 106, and the melting point of the metal material forming the current collectors 101 and 102. By controlling the pressure in this manner, even low boiling point solvents such as water and lower alcohols can be used as liquid heat transfer medium. Water is particularly suitable as a liquid heat medium because it is easy to handle and is inexpensive.

As a heating method using a liquid heat medium, for example, a method of immersing the bipolar electrode 130 in the liquid heat medium, a method of pouring the liquid heat medium over the bipolar electrode 130, of the heat medium is sprayed onto the bipolar electrodes 130 . Among these methods, the liquid heat medium can be brought into sufficient contact with the substrate 111 and the adhesive 106, and the substrate 111 and the adhesive 106 can be sufficiently heated. A method of immersing the bipolar electrode 130 therein is preferred.

Solid heat transfer mediums include high-temperature lumps. Examples include high-temperature metals, ceramics, and sand. As a heating method using a solid heat medium, for example, there is a method of covering part or all of the surface of the bipolar electrode 130 with a high-temperature mass and leaving the surface of the bipolar electrode 130 with a granular or powdery heat medium. , and a method of spraying a granular or powdery heat medium onto the bipolar electrodes 130.

The heating of the bipolar electrode 130 in the resin removal step causes one or more of softening, melting, and thermal decomposition to occur in one of the substrate 111 and the adhesive 106, and softening, melting, and thermal decomposition in the other. It may be done so that it does not occur, or it may be done so that one or more of softening, melting, and thermal decomposition occur in both.

In addition, when heating is performed so that one or more of softening, melting, and thermal decomposition occur in both the substrate 111 and the adhesive 106, the phenomenon caused by heating is the same for the substrate 111 and the adhesive 106. may be different. For example, bipolar electrode 130 may be heated such that both substrate 111 and adhesive 106 melt, or bipolar electrode 130 may be heated such that substrate 111 melts and adhesive 106 thermally decomposes. .

Here, one specific example of the material recovery method for the bipolar storage battery according to this embodiment will be shown. In this specific example, the metal material forming the current collectors 101 and 102 is lead (melting point 327.5° C.), the resin forming the substrate 111 is ABS resin (melting point 100 to 125° C.), and the adhesive The resin forming 106 is an epoxy resin (thermal decomposition temperature of 150° C. or higher). Moreover, the heat medium used for heating the bipolar electrodes 130 is water.

The bipolar electrode 130 is immersed in water and heated under a pressure of over 1 atmosphere, and the pressure is controlled so that the temperature of the water is above the thermal decomposition temperature of the epoxy resin and below the melting point of lead. As a result, the substrate 111 is melted and fluidized and the adhesive 106 is thermally decomposed, but the current collectors 101 and 102 are not melted, so that the substrate 111 and the adhesive 106 are removed from the bipolar electrode 130 and the current collectors are removed. 101, 102 can be recovered.

Also, when the pressure is controlled so that the temperature of the water is equal to or higher than the melting point of the ABS resin and lower than the thermal decomposition temperature of the epoxy resin, the substrate 111 melts and becomes fluid, but the adhesive 106 does not thermally decompose and collects current. The bodies 101, 102 also do not melt. Therefore, although the substrate 111 is removed from the bipolar electrode 130, the adhesive 106 is not removed, and the current collectors 101 and 102 with the adhesive 106 adhered are obtained. In such a case, in order to recover the current collectors 101 and 102, it is necessary to perform a further step of removing the adhesive 106 from the current collectors 101 and 102 to which the adhesive 106 is adhered.

As described above, when the bipolar electrode 130 is heated in the resin removal step, one or both of the substrate 111 and the adhesive 106 are removed from the bipolar electrode 130. However, the softening temperature, melting point, and thermal decomposition of the resin forming the substrate 111 Depending on the combination of the temperature, the softening temperature of the resin forming the adhesive 106, the melting point, the thermal decomposition temperature, and the heating temperature in the resin removal step, only the substrate 111 is removed and only the adhesive 106 is removed. , both the substrate 111 and the adhesive 106 may be removed.

When only the substrate 111 is removed by softening, melting, or thermal decomposition, the current collectors 101 and 102 with the adhesive 106 adhered are obtained. The current collectors 101 and 102 can be recovered. Examples of methods for removing the adhesive 106 from the current collectors 101 and 102 include the following methods.

That is, a method of mechanically removing the adhesive 106 by applying force using a tool or the like, a method of dissolving the adhesive 106 using a solvent, a method of chemically decomposing the adhesive 106 using chemicals, A method of softening, melting, pyrolyzing, or burning the adhesive 106 by applying heat, a method of contracting the current collectors 101 and 102 and the adhesive 106 by cooling, and causing linear expansion of the current collectors 101 and 102 and the adhesive 106 A method of exfoliation based on the difference in coefficients can be mentioned.

Note that if the substrate 111 is softened by heating, it may take a long time to remove the substrate 111 from the bipolar electrode 130 . In that case, in a state in which the softened substrate 111 is not removed from the bipolar electrode 130 and is attached to the current collectors 101 and 102, the substrate 111 or the current collectors 101 and 102 may be removed by using a tool or the like. A force may be applied to separate the substrate 111 and the current collectors 101 and 102 .

Next, when only the adhesive 106 is removed by softening, melting, or thermal decomposition, the substrate 111 and the current collectors 101 and 102 are separately separated, so the substrate 111 and the current collectors 101 and 102 are recovered. be able to. In this case, the substrate 111 can be easily recovered together with the metal material. If the substrate 111 is made of a thermoplastic resin, the recovered substrate 111 can be easily melted and reused. can be used for the purpose of

Note that if the adhesive 106 is softened by heating, it may take a long time to remove the adhesive 106 from the bipolar electrode 130 . In this case, in a state in which the softened adhesive 106 is not removed from the bipolar electrode 130 but adheres to the substrate 111 and the current collectors 101 and 102, the substrate 111 and the adhesive 106 are removed by using a tool or the like. Alternatively, force may be applied to the current collectors 101 and 102 to separate the adhesive 106 from the substrate 111 and the current collectors 101 and 102 .

Next, when both the substrate 111 and the adhesive 106 are removed by softening, melting, or thermal decomposition, the current collectors 101 and 102 can be recovered as they are.
Note that if the substrate 111 and the adhesive 106 are softened by heating, it may take a long time to remove the substrate 111 and the adhesive 106 from the bipolar electrode 130 . In this case, the softened substrate 111 and the adhesive 106 are removed from the bipolar electrode 130 and adhered to the current collectors 101 and 102, and the substrate 111 and the adhesive 106 are removed by using a tool or the like. Alternatively, force may be applied to the current collectors 101 and 102 to separate the substrate 111 and the adhesive 106 from the current collectors 101 and 102 .

By dismantling the bipolar lead-acid battery 1 and heating the bipolar electrode 130 in this way, the current collectors 101 and 102 can be separated and recovered. can easily recover the metal material (lead or lead alloy) from the bipolar electrode 130 of the bipolar lead-acid battery 1 . The recovered metal material may be reused for manufacturing a bipolar lead-acid battery, or may be used for other purposes.

Further, according to the material recovery method of the bipolar storage battery according to the present embodiment, the metal conductive auxiliary member for assisting the conductivity and the metal conductive auxiliary member for facilitating the adhesion of the active material are used for current collection. If provided on the body 101, 102, this metal conductive auxiliary member can also be recovered. The recovered metallic conductive auxiliary members may be reused for manufacturing bipolar lead-acid batteries, or may be used for other purposes, as in the case of the current collectors 101 and 102 .

Furthermore, according to the bipolar storage battery material recovery method according to the present embodiment, it is possible to easily recover the positive electrode active material 103 and the negative electrode active material 104 from the bipolar electrode 130 of the bipolar lead-acid battery 1 . In the case of the bipolar lead-acid battery 1 , the lead, which is the negative electrode active material 104 , is joined to the current collector 102 of the negative electrode 110 , and thus is collected together with the current collector 102 . On the other hand, lead oxide, which is the positive electrode active material 103, adheres to the current collector 101 of the positive electrode 120, and thus may peel off from the current collector 101 of the positive electrode 120 when the bipolar electrode 130 is heated. is high. Therefore, the lead oxide, which is the positive electrode active material 103, is preferably recovered separately after the resin removing step is completed.

Furthermore, the material recovery method of the bipolar type storage battery according to the present embodiment can recover metal materials and the like from the used bipolar type lead acid battery 1 as described above. It is also applicable to the bipolar lead-acid battery 1 after use, and metal materials and the like can be recovered in the same manner as in the case of the bipolar lead-acid battery 1 after use.

DESCRIPTION OF SYMBOLS 1... Bipolar lead-acid battery 11... 1st plate 12... 2nd plate 13... 3rd plate 14... 4th plate 101... Current collector 102... Current collector DESCRIPTION OF SYMBOLS 103... Active material for positive electrodes 104... Active material for negative electrodes 105... Electrolyte layer 106... Adhesive 107... Negative electrode terminal 108... Positive electrode terminal 110... Negative electrode 111... Substrate 120... Positive electrode 130... Bipolar electrode

Claims (5)

Equipped with a bipolar electrode in which a positive electrode is formed on one surface of a resin substrate and a negative electrode is formed on the other surface,
The positive electrode includes a current collector made of a metal material and adhered to the one surface of the substrate via a resin adhesive, and a positive electrode active material disposed on the current collector. prepared,
The negative electrode includes a current collector made of a metal material and adhered to the other surface of the substrate via a resin adhesive, and a negative electrode active material disposed on the current collector. A material recovery method for a bipolar storage battery comprising:
a dismantling step of dismantling the bipolar storage battery to separate the bipolar electrodes;
The bipolar electrode obtained in the dismantling step is heated to a temperature at which one or both of the substrate and the adhesive are softened, melted, or thermally decomposed, and the metal forming the current collectors of the positive electrode and the negative electrode. a resin removal step of heating below the melting point of the material to remove one or both of the substrate and the adhesive from the bipolar electrode;
A material recovery method for a bipolar storage battery having 2. The material recovery method for a bipolar storage battery according to claim 1, wherein the resin forming said substrate is a thermoplastic resin. In the resin removal step, a heating method in which the bipolar electrodes are housed in a heating device for heating, a heating method by electromagnetic induction heating, a heating method by infrared irradiation, and a heating method in which a high-temperature heat medium is brought into contact with the bipolar electrodes. 3. The material recovery method for a bipolar storage battery according to claim 1, wherein the bipolar electrode is heated by at least one of the methods. 4. The bipolar storage battery material according to claim 3, wherein the heating method of bringing the high-temperature heat medium into contact with the bipolar electrode is a method of heating the bipolar electrode by immersing the bipolar electrode in a liquid heat medium. collection method. The bipolar type according to any one of claims 1 to 4, wherein the metal material forming the current collectors of the positive electrode and the negative electrode is lead or a lead alloy, and the bipolar type storage battery is a bipolar lead acid battery. A material recovery method for storage batteries.

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