Method for processing battery and coated body

Abstract

The main purpose of the present disclosure is to provide a method for processing a battery capable of deactivating a battery satisfactorily. In the present disclosure, provided is a method for processing a battery having an immersion step in which a battery including an Al terminal is immersed in a processing liquid containing water and a supporting electrolyte, and the voltage of the battery is reduced by an external short circuit through the processing liquid, and in the immersion step, the voltage of the battery is reduced by an external short circuit through the processing liquid. The problem is solved by disposing a conductive coating body so as to cover at least a portion of the Al terminal, and electrically connecting the processing liquid and the Al terminal via the coating body.

Description

Technical Field

[0001] The present disclosure relates to a battery processing method and a battery package. Background Art

[0002] Batteries typically have terminals for extracting electricity from the electrode assembly, which is a power generation element. For example, Patent Document 1 discloses a battery module comprising laminated, exterior-packaged flat batteries having a positive terminal lead and a negative terminal lead, and discloses that the positive terminal lead is made of aluminum.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2007-257849 Summary of the Invention

[0006] In battery recycling, it is desirable to reduce the residual voltage of the battery and deactivate it. For example, a method for deactivating the battery can be immersing the battery in a treatment solution (e.g., salt water) to cause an external short circuit. In batteries with aluminum terminals (Al terminals), the Al terminals degrade due to the treatment solution, making it difficult to deactivate the battery effectively.

[0007] The present disclosure has been made in view of the above circumstances, and a main object of the present disclosure is to provide a battery treatment method that can effectively deactivate the battery.

[0008] [1] A method for processing a battery,

[0009] The battery treatment method includes an immersion step in which the battery including the Al terminal is immersed in a treatment solution, and the voltage of the battery is reduced by an external short circuit through the treatment solution.

[0010] The treatment solution contains water and a supporting electrolyte.

[0011] In the dipping step, a conductive coating is used and arranged to cover at least a portion of the Al terminal, so that the treatment liquid and the Al terminal are electrically connected via the coating.

[0012] [2] In the battery processing method described in [1],

[0013] The above-mentioned coating body has a conductive component,

[0014] In the dipping step, the coating is placed on the Al terminal so that the conductive member is electrically connected to the Al terminal.

[0015] [3] In the battery processing method described in [2],

[0016] The conductive member is a metal member.

[0017] [4] In the battery processing method described in [3],

[0018] The material of the above-mentioned metal parts is aluminum or aluminum alloy.

[0019] [5] In the battery processing method described in [3],

[0020] The material of the above-mentioned metal parts is iron or iron alloy.

[0021] [6] In the battery processing method described in [3],

[0022] The material of the metal component is magnesium, magnesium alloy, zinc or zinc alloy.

[0023] [7] In the battery processing method described in any one of [3] to [6],

[0024] The metal member has a conductive resin portion on a surface facing the Al terminal.

[0025] [8] In the battery processing method described in any one of [3] to [6],

[0026] The metal member has a plated portion on a surface facing the Al terminal.

[0027] [9] In the battery processing method described in any one of [2] to [8],

[0028] The covering body further comprises a first component, a second component, and a connecting component configured to connect the first component and the second component.

[0029] In the above-mentioned impregnation process, the above-mentioned first component and the above-mentioned second component are placed opposite to each other with the above-mentioned Al terminal between them, and the relative positions of the above-mentioned first component and the above-mentioned second component are fixed by the above-mentioned connecting component, so that the above-mentioned coating is arranged on the above-mentioned Al terminal, and the above-mentioned conductive component is arranged between the above-mentioned first component and the above-mentioned Al terminal.

[0030]

[10] In the battery processing method described in [1],

[0031] The covering body includes a first component, a second component, and a connecting component configured to connect the first component and the second component.

[0032] At least one of the first component and the second component is a conductive component,

[0033] In the dipping step, the first member and the second member are opposed to each other with the Al terminal interposed therebetween, and the relative positions of the first member and the second member are fixed by the connecting member, thereby placing the covering body on the Al terminal.

[0034]

[11] In the battery processing method described in [1],

[0035] The above-mentioned covering body is a hollow component having a space portion.

[0036] The hollow component is a conductive component.

[0037] In the dipping step, the Al terminal is inserted into the space, whereby the coating body is disposed on the Al terminal.

[0038]

[12] In the battery processing method described in [1],

[0039] The covering body includes a first member and a pair of claw members respectively arranged on a pair of opposite sides of the first member.

[0040] At least one of the first component and the claw component is a conductive component.

[0041] In the dipping step, the Al terminal is fixed by the pair of claw members, whereby the package is placed on the Al terminal.

[0042]

[13] In the battery processing method described in any one of [1] to

[12] ,

[0043] The battery comprises an electrode body, an exterior body covering the electrode body, and the Al terminal electrically connected to the electrode body and partially exposed from the exterior body.

[0044] In the dipping step, the covering body is arranged so as to cover at least a boundary between the Al terminal and the exterior body.

[0045]

[14] In the battery processing method described in any one of [1] to

[13] ,

[0046] The above-mentioned battery has a laminated outer casing.

[0047]

[15] In the battery processing method described in any one of [1] to

[14] ,

[0048] The above-mentioned battery is a solid-state battery.

[0049]

[16] A coating used in the battery processing method described in any one of [1] to

[15] , wherein:

[0050] The above-mentioned coating body corresponds to any of the following coating bodies (i) to (iv),

[0051] (i) the coating has a conductive member,

[0052] (ii) the covering body comprises a first member, a second member, and a connecting member configured to connect the first member and the second member, at least one of the first member and the second member being a conductive member;

[0053] (iii) the covering body is a hollow member having a space portion, and the hollow member is a conductive member,

[0054] (iv) The covering body includes a first member and a pair of claw members disposed on a pair of opposing sides of the first member, and at least one of the first member and the claw members is a conductive member.

[0055] In the present disclosure, there is an effect of being able to deactivate the battery in a favorable manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1A 、 Figure 1B 1 and 2 are schematic top and side views respectively illustrating a battery in the present disclosure.

[0057] Figure 2 is a schematic side view illustrating a method for handling a battery in the present disclosure.

[0058] Figure 3A 、 Figure 3B 、 Figure 3C 、 Figure 3D A schematic plan view and a schematic cross-sectional view respectively illustrate a portion of a battery and a package in the present disclosure.

[0059] Figure 4A 、 Figure 4B They are respectively a perspective schematic diagram and a side schematic diagram illustrating the covering body in the present disclosure.

[0060] Figure 5A 、 Figure 5B It is a perspective schematic diagram and a side schematic diagram illustrating the covering body in the present disclosure.

[0061] Figure 6 It is a perspective schematic diagram illustrating the covering body in the present disclosure.

[0062] Figure 7 It is a perspective schematic diagram illustrating the covering body in the present disclosure.

[0063] Figure 8 It is a perspective schematic diagram illustrating the covering body in the present disclosure.

[0064] Figure 9 It is a perspective schematic diagram illustrating the covering body in the present disclosure.

[0065] Figure 10A 、 Figure 10B Each of them is a schematic plan view illustrating the arrangement of the covering body in the present disclosure.

[0066] Figure 11A 、 Figure 11B Each is a schematic cross-sectional view illustrating an electrode body in the present disclosure.

[0067] Figure 12 It is a graph showing the results of the immersion test of the comparative example.

[0068] Figure 13 This is a graph showing the results of the immersion test in Examples.

[0069] (Explanation of Symbols)

[0070] 1: Negative electrode current collector; 2: Negative electrode active material layer; 3: Electrolyte layer; 4: Positive electrode active material layer; 5: Positive electrode current collector; 10: Electrode body; 20: Outer casing; 30: Terminal; 40: Treatment bath; 50: Treatment liquid; 60: Encapsulation body; 100: Battery. DETAILED DESCRIPTION

[0071] The following drawings are used to describe in detail the battery processing method and the package body in the present disclosure. The figures shown below are schematic drawings, and the size and shape of each part are exaggerated appropriately for ease of understanding. In addition, in this specification, when expressing a scheme for configuring other components with respect to a certain component, when simply expressed as "upper" or "lower", unless otherwise specified, it includes both the case where other components are configured directly above or below a certain component in a manner connected to the certain component, and the case where other components are configured above or below a certain component separated by other components.

[0072] A. Battery disposal methods

[0073] Figure 1A 、 Figure 1B 1 and 2 are schematic top views and side views of the battery disclosed herein. Figure 1A 、 Figure 1B As shown, the battery 100 includes an electrode body 10, an outer body 20 covering the electrode body 10, and terminals 30 (30A, 30B) electrically connected to the electrode body 10 and partially exposed from the outer body 20. At least one of the terminals 30A and 30B is an Al terminal. Figure 1A 、 Figure 1B In FIG. 3 , terminal 30A corresponds to A1 terminal 30X.

[0074] Figure 2is a side view schematic diagram illustrating the battery processing method of the present disclosure. Figure 2 As shown, a treatment liquid 50 is added to the treatment bath 40, and the battery 100 is immersed in the treatment liquid 50. Terminals 30A and 30B are electrically connected via the treatment liquid 50, resulting in an external short circuit and a decrease in the voltage of the battery 100. In the present disclosure, a conductive coating 60 is used and arranged to cover at least a portion of the Al terminal 30X. This electrically connects the treatment liquid 50 and the Al terminal 30X via the coating 60.

[0075] According to the present disclosure, a conductive coating is configured in a manner covering the Al terminal, so that the battery can be deactivated well. As mentioned above, when recycling the battery, it is desired to reduce the residual voltage of the battery and deactivate the battery. By deactivating the battery, subsequent processes such as the battery disassembly process can be carried out safely. As a method for deactivating the battery, a method of externally short-circuiting the battery by immersing it in a treatment liquid (such as salt water) can be cited. In a battery including an Al terminal, the Al terminal deteriorates due to the treatment liquid, and it is sometimes difficult to deactivate the battery well. For example, when the Al terminal is corroded (dissolved) due to the treatment liquid and the Al terminal exposed from the outer body slips off, it is sometimes impossible to reduce the residual voltage by external short-circuiting, or to significantly reduce the reduction rate.

[0076] In contrast, the present disclosure employs a conductive coating that covers the Al terminal. This prevents degradation of the Al terminal due to the treatment fluid. Consequently, when the battery is immersed in the treatment fluid, an external short circuit is maintained, effectively deactivating the battery.

[0077] The battery impregnation method disclosed herein includes an impregnation step in which a battery including an Al terminal is immersed in a treatment solution, causing an external short circuit through the treatment solution, thereby reducing the battery voltage. Furthermore, the present invention utilizes a conductive coating, which is arranged to cover at least a portion of the Al terminal, so that the treatment solution and the Al terminal are electrically connected via the coating. Furthermore, the battery treatment method disclosed herein does not require complete prevention of Al terminal degradation; it suffices to utilize the coating to suppress Al terminal degradation to a level that effectively deactivates the battery.

[0078] 1. Encapsulation

[0079] The coating in the present disclosure is conductive. In addition, the coating is electrically connected to the Al terminal. The coating is preferably in direct surface contact with the main surface of the Al terminal, or in contact with it via other layers. By the coating being in surface contact with the main surface of the Al terminal, the main surface of the Al terminal is protected by the coating. The area of the main surface of the Al terminal protected by the coating is prevented from contacting the processing liquid, thereby suppressing the degradation of the Al terminal. The coating in the present disclosure is described below in four embodiments.

[0080] (1) First embodiment

[0081] The coating in the first embodiment includes a conductive member. In the dipping step, the coating is placed on the Al terminal so that the conductive member and the Al terminal are electrically connected.

[0082] Here, Figure 3A is a schematic plan view illustrating a portion of the battery (before the package is arranged) in the present disclosure. Figure 3B yes Figure 3A AA cross-section diagram. Figure 3C 1 is a schematic top view illustrating a portion of the battery (after configuring the package body) in the present disclosure. Figure 3D yes Figure 3C AA cross-section diagram. In addition, Figure 4A is a perspective schematic diagram illustrating the package body in the present disclosure, Figure 4B 1 is a side view schematic diagram illustrating the package in the present disclosure. Figure 4A In the description, the connection parts are omitted.

[0083] like Figure 3A 、 Figure 3B As shown, the Al terminal 30X is electrically connected to the electrode body 10 and a portion thereof is exposed from the outer package 20. Figure 4A 、 Figure 4B The covering body 60 shown in FIG. 1 includes a conductive component 61, and further includes a first component 62a, a second component 62b, and a connecting component 63. Figure 3C 、 Figure 3D As shown in FIG. 1 , the coating (conductive component 61) is arranged on the Al terminal 30X in such a manner that the conductive component 61 and the Al terminal 30X are electrically connected. Figure 3C As shown, the conductive component 61 may be arranged so as to overlap a portion of the Al terminal 30X when viewed in the thickness direction (the front and back direction of the paper). On the other hand, although not specifically shown, the conductive component may be arranged so as to cover the entire Al terminal when viewed in the thickness direction.

[0084] like Figure 4A 、 Figure 4BAs shown, the coating 60 in the first embodiment has a conductive component 61. During the impregnation process, the conductive component is electrically connected to the Al terminal. During the impregnation process, the conductive component is preferably in direct surface contact with the main surface of the Al terminal, or in contact with it via other layers. By making the conductive component in surface contact with the main surface of the Al terminal, the main surface of the Al terminal is protected by the conductive component. The area of the main surface of the Al terminal that is protected by the conductive component is inhibited from contacting the processing liquid, thereby inhibiting the degradation of the Al terminal. In particular, when the conductive component is less likely to be degraded by the processing liquid than the Al terminal, it is possible to maintain an external short circuit while suppressing the degradation of the Al terminal, so that the battery can be deactivated well.

[0085] Examples of conductive components include metal components and carbon components, with metal components being preferred. Examples of metal components include aluminum and aluminum alloys. Aluminum alloys are alloys containing aluminum as the main metal component. In aluminum alloys, the ratio of aluminum to all metal components is, for example, 50% by weight or greater, 70% by weight or greater, or even 90% by weight or greater.

[0086] The material of the metal part can also be a material with a smaller ionization tendency than the Al terminal (a material with a high natural potential). Regarding materials with a smaller ionization tendency than the Al terminal, they have high tolerance to the treatment liquid. As such materials, for example, iron, iron alloys, titanium, titanium alloys, copper, copper alloys, lead, and lead alloys can be cited, among which iron alloys are preferred and stainless steel is particularly preferred. On the other hand, in the case where the material of the metal part is a material with a smaller ionization tendency than the Al terminal, when there is a treatment liquid between the metal part and the Al terminal, the Al terminal is prone to corrosion (electrochemical corrosion). Therefore, in the impregnation process, it is preferred to make the metal part and the Al terminal close to each other in a manner that prevents the treatment liquid from invading the space between the metal part and the Al terminal. Alternatively, the metal part preferably has a conductive resin portion or a plating portion described later on the surface of the Al terminal side. In addition, in the battery processing method disclosed in the present invention, it is not necessary to completely prevent the corrosion of the Al terminal, and it is sufficient to suppress the corrosion of the Al terminal to the extent that the battery loses its activity well by using a conductive part.

[0087] The material of the metal part can also be a material with an ionization tendency of the same degree as that of the Al terminal, or a material with an ionization tendency greater than that of the Al terminal (a material with a low natural potential). As such a material, for example, magnesium, magnesium alloys, zinc, and zinc alloys can be cited. When such a material is used, the Al terminal is not easily corroded even if a treatment liquid is present between the metal part and the Al terminal. On the other hand, due to the progress of corrosion of the metal part, for example, it is preferable to set the thickness of the metal part to be sufficiently thick. In addition, the metal part can also be an Al-containing part having Al as its main component.

[0088] The shape of the conductive component is not particularly limited, and may be, for example, a flat plate. Furthermore, the thickness of the conductive component is not particularly limited, but is preferably greater than the thickness of the Al terminal. The ratio of the thickness of the conductive component to the thickness of the Al terminal may be, for example, 1.2 times or greater, 1.5 times or greater, 2 times or greater, or 5 times or greater. Alternatively, the ratio is not particularly limited, and may be, for example, 20 times or less, or 15 times or less.

[0089] If the conductive component is a metal component, the metal component may have a conductive resin portion on the surface facing the Al terminal. Providing the conductive resin portion can suppress corrosion of the Al terminal, even if the metal component is made of a material with a lower ionization tendency than the Al terminal.

[0090] The conductive resin portion includes, for example, resin (including rubber) and a conductor. Examples of the resin include polyolefin resins such as polyethylene, polypropylene, and polystyrene; imide resins such as polyimide and polyamideimide; amide resins such as polyamide; acrylic resins such as polymethyl acrylate, polyethyl acrylate, polypropyl acrylate, polybutyl acrylate, polyhexene acrylate, poly2-ethylhexyl acrylate, polydecyl acrylate, and polyacrylic acid; methacrylic resins such as polymethyl methacrylate, polyethylene methacrylate, polybutyl methacrylate, poly2-ethylhexyl methacrylate, and polymethacrylic acid; carboxylic acid resins such as polyitaconic acid, polycrotonic acid, polyfumaric acid, polyangelic acid, and carboxymethyl cellulose; fluorine-based resins such as polyvinylidene fluoride (PVDF), polyvinylidene fluoride-polyhexafluoropropylene copolymer (PVDF-HFP), and polytetrafluoroethylene; and rubbers such as butadiene rubber, hydrogenated butadiene rubber, styrene butadiene rubber (SBR), hydrogenated styrene butadiene rubber, nitrile butadiene rubber, hydrogenated nitrile butadiene rubber, ethylene propylene rubber, and fluororubber. On the other hand, examples of the above-mentioned conductor include carbon materials, metal particles, and conductive polymers. Examples of the carbon material include granular carbon materials such as acetylene black (AB) and Ketjen black (KB), and fibrous carbon materials such as carbon fibers, carbon nanotubes (CNTs), and carbon nanofibers (CNFs). Examples of methods for forming the conductive resin portion include applying a slurry containing a resin, a conductor, and a solvent to a metal component and drying the slurry.

[0091] When the conductive component is a metal component, the metal component may also have a plated portion on the surface of the Al terminal side. By providing the plated portion, the adhesion between the conductive component and the Al terminal is improved. The material of the plated portion is not particularly limited. For example, a material with a lower ionization tendency than the Al terminal can be cited. Examples of such materials include gold, silver, and palladium. Examples of methods for forming the plated portion include electroplating and electroless plating.

[0092] In the first embodiment, the method of fixing the conductive component to the Al terminal is not particularly limited, and any method may be used. For example, the conductive component may be fixed to the Al terminal by clamping the conductive component and the Al terminal with a clamp. Figure 4A 、 Figure 4B As shown in FIG. 1 , the covering body 60 in the first embodiment may also include a first component 62a, a second component 62b, and a connecting component 63 in addition to the conductive component 61. Figure 3C 、 Figure 3D As shown, the first component 62a and the second component 62b are placed opposite to each other with the Al terminal 30X interposed therebetween, and the relative positions of the first component 62a and the second component 62b are fixed by the connecting component 63, thereby arranging the package 60 to the Al terminal 30X. In addition, the conductive component 61 is arranged between the first component 62a and the Al terminal 30X. Figure 4A 、 Figure 4B In the embodiment, a conductive component 61 is arranged on one side of the Al terminal 30X. Figure 5A 、 Figure 5B As shown in FIG. 1 , a conductive member 61 a and a conductive member 61 b are respectively arranged on both surfaces of the Al terminal 30X.

[0093] At least one of the first and second components may also be a conductive component. The conductive component is the same as described above. On the other hand, since the covering in the first embodiment includes at least the conductive component, the first and second components may each be made of a non-conductive material. Examples of non-conductive materials include thermoplastic resins, rubber, and other resins. Furthermore, the shapes of the first and second components are not particularly limited, and may be, for example, flat plates.

[0094] (2) Second embodiment

[0095] The coating in the second embodiment includes a first component, a second component, and a connecting member configured to connect the first and second components. Furthermore, at least one of the first and second components is a conductive component. Furthermore, during the impregnation step, the first and second components are positioned opposite each other with the Al terminal interposed therebetween, and the connecting member is used to fix the relative positions of the first and second components, thereby placing the coating on the Al terminal.

[0096] Figure 6 1 is a side view schematic diagram illustrating the package in the present disclosure. Figure 6 In the figure, the description of the connecting parts is omitted. Figure 6The illustrated covering 60 includes a first component 62a and a second component 62b. At least one of the first component 62a and the second component 62b is a conductive component. The materials and shapes of the first component 62a and the second component 62b are the same as those described in the first embodiment. In addition, when the first component 62a is a metal component, the first component 62a may have a conductive resin portion on the surface on the Al terminal side, and may also have a plated portion. Similarly, when the second component 62b is a metal component, the second component 62b may have a conductive resin portion on the surface on the Al terminal side, and may also have a plated portion. The conductive resin portion and the plated portion are the same as those described in the first embodiment.

[0097] During the impregnation step, the first component may also be electrically connected to the Al terminal. During the impregnation step, the first component is preferably in direct surface contact with the main surface of the Al terminal, or in contact with it via another surface layer. Similarly, during the impregnation step, the second component may also be electrically connected to the Al terminal. During the impregnation step, the second component is preferably in direct surface contact with the main surface of the Al terminal, or in contact with it via another surface layer.

[0098] like Figure 4A 、 Figure 4B As shown, the first component 62a and the second component 62b may also have a hole H for inserting the connecting component 63. Figure 4B As shown, the relative positions of the first component 62a and the second component 62b are fixed by the connecting component 63, thereby arranging the package 60 to the Al terminal 30X. Figure 4B The connecting member 63 shown in FIG. 6 includes a rod-shaped member 63a and a fixing member 63b connected to the rod-shaped member 63a and having a fixing structure such as a screw structure. Figure 7 As shown, the connecting member 63 may also be a member having a curved structure. Figure 7 In the embodiment, the first member 62a, the second member 62b and the connecting member 63 are integrated.

[0099] (3) Third embodiment

[0100] The coating in the third embodiment is a hollow member having a space. Furthermore, the hollow member is a conductive member. Furthermore, in the impregnation step, the coating is positioned on the Al terminal by inserting the Al terminal into the space.

[0101] Figure 8 It is a perspective schematic diagram illustrating the covering body in the present disclosure. Figure 8 The illustrated covering 60 is a hollow member having a space α. An Al terminal (not shown) is inserted into the space α. The hollow member is a conductive member. The material of the conductive member is the same as that described in the first embodiment.

[0102] If the hollow component is a metal component, it may have a conductive resin portion on the surface of the Al terminal, or it may have a plated portion. The conductive resin portion and the plated portion are the same as those described in the first embodiment. Furthermore, during the impregnation step, the hollow component is electrically connected to the Al terminal. During the impregnation step, the hollow component is preferably in direct surface contact with the main surface of the Al terminal, or in contact with it via another surface.

[0103] (4) Fourth embodiment

[0104] The encapsulated body in the fourth embodiment includes a first member and a pair of claw members disposed on a pair of opposing sides of the first member. Furthermore, at least one of the first member and the claw members is a conductive member. Furthermore, during the impregnation step, the encapsulated body is positioned on the Al terminal by securing the Al terminal with the pair of claw members.

[0105] Figure 9 It is a perspective schematic diagram illustrating the covering body in the present disclosure. Figure 9 The illustrated covering body 60 includes a first component 62a and a pair of claw components 64 disposed on a pair of opposite sides of the first component 62a. An Al terminal (not shown) is fixed by the pair of claw components 64. In addition, at least one of the first component 62a and the claw component 64 is a conductive component. The material of the conductive component is the same as that described in the first embodiment described above. In addition, when the first component 62a is a metal component, the first component 62a may have a conductive resin portion on the surface on the Al terminal side, and may also have a plated portion. Similarly, when the claw component 64 is a metal component, the claw component 64 may have a conductive resin portion on the surface on the Al terminal side, and may also have a plated portion. The conductive resin portion and the plated portion are the same as those described in the first embodiment described above.

[0106] During the dipping process, the first component may also be electrically connected to the Al terminal. During the dipping process, the first component is preferably in direct surface contact with the main surface of the Al terminal, or in contact with it via another layer. Similarly, during the dipping process, the claw component may also be electrically connected to the Al terminal. During the dipping process, the claw component is preferably in direct surface contact with the side surface of the Al terminal, or in contact with it via another layer.

[0107] (5) Encapsulation

[0108] like Figure 10A As shown in FIG. 1 , the covering body 60 may be arranged so as to cover the entire Al terminal 30X when viewed from the thickness direction (z direction). Figure 10BAs shown in FIG, the covering body 60 may be arranged so as to cover a portion of the Al terminal 30X when viewed from the thickness direction (z direction). Figure 10B In the embodiment, the coating 60 is configured to selectively cover the region of the Al terminal 30X including the end portion on the outer body 20 side. By protecting the region (root region) of the Al terminal 30X including the end portion on the outer body 20 side, when the battery is immersed in the treatment liquid, the external short circuit can be further maintained, and the battery can be more effectively deactivated. In addition, "the coating is configured to selectively cover the region of the Al terminal including the end portion on the outer body side" means that, as shown in FIG. Figure 10B As shown in FIG. 1 , there is an area where the covering body 60 is not arranged on the side opposite to the outer body 20 in the root area. In addition, when viewed from the thickness direction, the area of the Al terminal is denoted as S. a The area of the overlapping region of the Al terminal and the conductive component in the package is defined as S b In the case of b Relative area S a The ratio (S b / S a ) is not particularly limited, and can be, for example, 10% or more, 30% or more, 50% or more, or 70% or more.

[0109] 2.Battery

[0110] like Figure 1A 、 Figure 1B As shown, the battery 100 generally includes an electrode body 10, an outer body 20 covering the electrode body 10, and terminals 30 (30A, 30B) electrically connected to the electrode body 10 and partially exposed from the outer body 20. In addition, at least one of the terminals 30A and 30B is an Al terminal. Figure 1A 、 Figure 1B In FIG. 3 , terminal 30A corresponds to A1 terminal 30X.

[0111] In this disclosure, a unit consisting of an electrode body, an outer casing, and a pair of terminals is sometimes referred to as a "cell." A battery treated by the treatment method disclosed herein may have a single cell or multiple cells. Multiple cells are typically stacked in the thickness direction. Furthermore, in this disclosure, a single coating may be used to cover all Al terminals in multiple cells stacked in the thickness direction.

[0112] (1)Terminal

[0113] The battery disclosed herein generally has a positive terminal and a negative terminal. At least one of the positive terminal and the negative terminal is an Al terminal. Among them, preferably, at least the positive terminal is an Al terminal. The Al terminal is a terminal containing at least aluminum. The Al terminal preferably contains aluminum as the main component of the metal component. In the Al terminal, the ratio of aluminum to all metal components is, for example, 50% by weight or more, or 70% by weight or more, or 90% by weight or more. Examples of the material of the Al terminal include aluminum and aluminum alloys.

[0114] The shape of the Al terminal is not particularly limited. In addition, although the thickness of the Al terminal is not particularly limited, the thinner the Al terminal, the greater the impact of the degradation of the Al terminal caused by the processing liquid. The thickness of the Al terminal refers to the length of the Al terminal in the normal direction of the main surface (the surface with the largest area) of the Al terminal. The thickness of the Al terminal is, for example, less than 2 mm, or less than 1.5 mm, or less than 1.0 mm, or less than 0.8 mm, or less than 0.6 mm. On the other hand, the thickness of the Al terminal is, for example, more than 0.1 mm.

[0115] (2) Electrode body

[0116] The electrode assembly in the present disclosure functions as a power generation element of a battery. The electrode assembly typically includes a positive electrode current collector, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector in this order in the thickness direction.

[0117] Figure 11A 、 Figure 11B 1 is a schematic cross-sectional view illustrating an electrode body in the present disclosure. Figure 11A The electrode body 10 shown includes, in order along the thickness direction (z direction), a negative electrode current collector 1, a negative electrode active material layer 2, an electrolyte layer 3, a positive electrode active material layer 4, and a positive electrode current collector 5. Furthermore, the negative electrode current collector 1 has a negative electrode tab 1t for connection to a negative electrode terminal (not shown), and the positive electrode current collector 5 has a positive electrode tab 5t for connection to a positive electrode terminal (not shown).

[0118] Figure 11B The electrode body 10 shown has a negative electrode collector 1, a negative electrode active material layer 2x, an electrolyte layer 3x, a positive electrode active material layer 4x and a positive electrode collector 5x arranged in sequence in the thickness direction (z direction) from one side of the negative electrode collector 1, and a negative electrode active material layer 2y, an electrolyte layer 3y, a positive electrode active material layer 4y and a positive electrode collector 5y arranged in sequence in the thickness direction (z direction) from the other side of the negative electrode collector 1.

[0119] exist Figure 11A 、 Figure 11BIn the embodiment, the positive electrode tab 5t and the negative electrode tab 1t are arranged on the side of the electrode body 10 in a manner opposite to each other, forming a so-called two-pole tab structure. On the other hand, although not specifically shown in the figure, the positive electrode tab and the negative electrode tab can also be arranged on the same side of the electrode body to form a so-called single-pole tab structure. Figure 11A 、 Figure 11B As shown, the electrode body 10 may also be a single-piece type. Furthermore, although not specifically shown, the electrode body may also be a wound type. Furthermore, a unit consisting of a positive electrode active material layer, an electrolyte layer, and a negative electrode active material layer is sometimes referred to as a "power generation unit." The electrode body in the present disclosure may have a single power generation unit or multiple power generation units. Multiple power generation units are typically stacked in the thickness direction.

[0120] The positive electrode active material layer contains at least a positive electrode active material. The positive electrode active material layer may also contain at least one of an electrolyte, a conductive material, and a binder. As the positive electrode active material, for example, an oxide active material can be cited. As the oxide active material, for example, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2、LiNi 0.8 Co 0.15 Al 0.05 O2 and other rock salt layer type active materials, LiMn2O4 and other spinel type active materials, LiFePO4 and other olivine type active materials. The shape of the positive electrode active material is, for example, particulate.

[0121] The electrolyte may be either a solid electrolyte or a liquid electrolyte (electrolyte). The solid electrolyte may be either an organic solid electrolyte such as a gel electrolyte or an inorganic solid electrolyte such as a sulfide solid electrolyte or an oxide solid electrolyte. Among them, the solid electrolyte is preferably a sulfide solid electrolyte. The reason for this is that the ion conductivity is high. On the other hand, the liquid electrolyte is not particularly limited and a known electrolyte can be used. In addition, as a conductive material, for example, a carbon raw material can be mentioned. In addition, as an adhesive, for example, a rubber-based adhesive and a fluoride-based adhesive can be mentioned.

[0122] The negative electrode active material layer contains at least a negative electrode active material. The negative electrode active material layer may also contain at least one of an electrolyte, a conductive material, and a binder. Examples of the negative electrode active material include metal active materials such as Li, Si, and Sn, carbon active materials such as graphite, and Li4Ti5O. 12 Oxide active substances.

[0123] The electrolyte layer is arranged between the positive electrode active material layer and the negative electrode active material layer, and contains at least an electrolyte. The electrolyte can be either a solid electrolyte or a liquid electrolyte. Regarding the electrolyte, the same as above. The electrolyte layer can also be a solid electrolyte layer containing a solid electrolyte. Furthermore, the solid electrolyte is preferably a sulfide solid electrolyte. In addition, generally speaking, a battery having an electrolyte layer containing an inorganic solid electrolyte is also called a solid battery. A solid battery can be either a semi-solid battery or a fully solid battery. In the present disclosure, a semi-solid battery is a battery in which the electrolyte layer has an inorganic solid electrolyte and a liquid component (such as an ionic liquid). In the present disclosure, a fully solid battery is a battery in which the electrolyte layer has only an inorganic solid electrolyte as an electrolyte.

[0124] The positive electrode current collector collects current from the positive electrode active material layer. Examples of materials for the positive electrode current collector include metals such as aluminum, SUS, and nickel. Examples of shapes for the positive electrode current collector include foil. The positive electrode current collector typically has a positive electrode tab for connection to the positive electrode terminal. Furthermore, the negative electrode current collector collects current from the negative electrode active material layer. Examples of materials for the negative electrode current collector include metals such as copper, SUS, and nickel. Examples of shapes for the negative electrode current collector include foil. The negative electrode current collector typically has a negative electrode tab for connection to the negative electrode terminal.

[0125] (3)Exterior body

[0126] The outer body in the present disclosure can be either a laminated outer body or a shell-type outer body. The laminated outer body is also called a bag-type outer body, which is an outer body using a laminated film. The laminated outer body has at least an inner resin layer and a metal layer. The inner resin layer functions as a sealant layer. The inner resin layer preferably contains a thermoplastic resin. Examples of the above-mentioned thermoplastic resin include polyolefins such as polyethylene and polypropylene, polystyrene, and polyvinyl chloride. The thickness of the inner resin layer is not particularly limited, and for example, is greater than 30 μm and less than 150 μm.

[0127] The metal layer functions as a barrier layer. Examples of the metal used in the metal layer include aluminum, aluminum alloys, and stainless steel. The thickness of the metal layer is not particularly limited, and is, for example, greater than 20 μm and less than 100 μm. In addition, the laminated outer body may also have an outer resin layer on the side opposite to the inner resin layer based on the metal layer. The outer resin layer functions as an insulating layer or a protective layer. The outer resin layer preferably contains a thermoplastic resin. Examples of the above-mentioned thermoplastic resin include polyester fibers such as polyethylene terephthalate (PET), and nylon. The thickness of the outer resin layer is not particularly limited, and is, for example, greater than 20 μm and less than 100 μm.

[0128] The shell-type outer casing is, for example, made of metal. Examples of materials for the shell-type outer casing include aluminum and aluminum alloys. Furthermore, the aluminum or aluminum alloy may be subjected to plastic working to achieve work-hardening. The thickness of the shell-type outer casing is not particularly limited and may be selected to achieve the desired rigidity.

[0129] (4)Battery

[0130] As the battery in the present disclosure, for example, secondary batteries such as lithium ion secondary batteries can be cited. In addition, as the use of the battery before being processed by the processing method in the present disclosure, for example, power sources for vehicles such as hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), electric vehicles (BEV), gasoline vehicles, and diesel vehicles can be cited. In particular, it is preferably a battery used in a driving power source for a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or an electric vehicle (BEV). It can be a battery used as a power source for a mobile body other than a vehicle (such as a railway, a ship, an airplane), or a battery used as a power source for electrical products such as an information processing device.

[0131] 3. Treatment fluid

[0132] The treatment liquid in the present disclosure contains water and a supporting electrolyte.

[0133] The supporting electrolyte is used to improve the conductivity of the treatment liquid. In addition, the supporting electrolyte generally does not have the function of suppressing the dissolution of the Al terminal. The supporting electrolyte has a cationic component and an anionic component. As the cationic component of the supporting electrolyte, for example, alkaline metal ions such as Na and K; alkaline earth metal ions such as Mg and Ca can be cited. On the other hand, as the anionic component of the supporting electrolyte, for example, chloride ions can be cited. Specific examples of the treatment liquid include NaCl, KCl, MgCl2, and CaCl2. In addition, the treatment liquid may contain only one supporting electrolyte or may contain two or more supporting electrolytes.

[0134] At least a portion of the supporting electrolyte is dissolved in water. The concentration of the supporting electrolyte in the treatment solution is not particularly limited, and for example, it is greater than 0.01 mol / kg and less than 5.0 mol / kg, or it can be greater than 0.1 mol / kg and less than 3.0 mol / kg. In the present disclosure, the above-mentioned concentration of the supporting electrolyte is defined as the ratio of the number of moles of the supporting electrolyte to the weight of the water contained in the treatment solution. In addition, as a method for preparing the treatment solution, for example, a method of dissolving the supporting electrolyte in water can be cited.

[0135] 4. Impregnation method

[0136] In the immersion process of the present disclosure, the battery including the Al terminal is immersed in a treatment solution, and the voltage of the battery is reduced by an external short circuit through the treatment solution. Figure 2 As shown, the treatment solution 50 is added to the treatment bath 40 , and the battery 100 is immersed in the treatment solution 50 .

[0137] The temperature of the treatment liquid during the immersion step is not particularly limited. For example, since the freezing point of salt water is approximately -20°C, the temperature of the treatment liquid is preferably -20°C or higher, and more preferably 0°C or higher. Alternatively, the temperature of the treatment liquid may be, for example, 60°C or lower, or 40°C or lower. Furthermore, the temperature of the treatment liquid during the immersion step may be the same as room temperature.

[0138] The treatment time in the immersion step is not particularly limited, but is preferably, for example, from the viewpoint of operability, 1 hour to 50 hours, and more preferably 2 hours to 25 hours.

[0139] B. Encapsulation

[0140] The covering body in the present disclosure is a covering body used in the above-mentioned battery processing method, and corresponds to any one of the following (i) to (iv).

[0141] (i) The coating has a conductive member.

[0142] (ii) The covering body includes a first member, a second member, and a connecting member configured to connect the first member and the second member, and at least one of the first member and the second member is a conductive member.

[0143] (iii) The covering body is a hollow member having a space portion, and the hollow member is a conductive member.

[0144] (iv) The covering body includes a first member and a pair of claw members disposed on a pair of opposing sides of the first member, and at least one of the first member and the claw members is a conductive member.

[0145] According to the present disclosure, the battery can be deactivated effectively by using the above-mentioned coating. The details of the coating are the same as those described in the above-mentioned "A. Battery Treatment Method", so the description here is omitted.

[0146] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any examples having substantially the same structure and achieving the same functions and effects as the technical concept described in the claims of the present disclosure are included in the technical scope of the present disclosure.

[0147] [Example]

[0148] [Comparative Example 1]

[0149] A laminated cell with Al terminals (0.4 mm thick) as the positive and negative terminals was prepared. The cell was fully charged, and voltage measurement terminals were attached to the positive and negative terminals, respectively. The cell was then placed in a treatment bath. A 3.5% by weight salt solution was then added to the treatment bath, and the cell was immersed. Changes in the cell voltage, cell temperature, and bath temperature were monitored. Figure 12 The results are shown.

[0150] like Figure 12 As shown in the figure, a sharp drop in voltage was observed 5 hours after the addition of salt water. Specifically, the voltage dropped sharply from approximately 2.3V to approximately 0.5V. On the other hand, visual inspection of the positive and negative terminals after 72 hours revealed that the positive terminal had fallen off. Furthermore, after 72 hours, the cell voltage was measured via the positive terminal remaining on the cell side, and the remaining voltage was approximately 2.2V, not approximately 0.5V. On the other hand, no sharp changes were observed in the cell temperature or the temperature within the cell.

[0151] [Example 1]

[0152] A laminated unit having Al terminals (thickness 0.4 mm) as positive and negative terminals was prepared. Figure 5A 、 Figure 5B As shown, two conductive members 61a and 61b were placed on both sides of the Al terminal 30X. Al plates (3 mm thick) were used as the conductive members, and the two conductive members were placed so as to cover the entire Al terminal when viewed from the thickness direction. The laminated cell was fully charged, and voltage measurement terminals were attached to the positive and negative terminals, respectively, before being placed in a treatment bath. Then, 3.5% by weight salt water was added to the treatment bath, and the laminated cell was immersed. Changes in the cell voltage and the cell temperature were monitored. Figure 13 The results are shown.

[0153] like Figure 13 As shown, it was confirmed that the voltage dropped significantly 11 hours after the addition of salt water. Specifically, the voltage dropped from about 1.9V to about 1.2V. On the other hand, after 25 hours, when the state of the positive terminal and the negative terminal was visually confirmed, it was confirmed that the positive terminal and the negative terminal had not fallen off. In addition, when the cell voltage was measured after 25 hours, the residual voltage was about 0.5V. On the other hand, no sudden change in the temperature in the cell was confirmed. In this way, it was confirmed that the use of a conductive coating can effectively deactivate the battery.

Claims

1. A method for processing a battery, wherein: The battery treatment method includes an immersion step in which a battery including an Al terminal is immersed in a treatment solution, and the voltage of the battery is reduced by an external short circuit through the treatment solution. The treatment solution contains water and a supporting electrolyte. In the dipping step, a conductive coating is used and arranged to cover at least a portion of the Al terminal, so that the processing liquid and the Al terminal are electrically connected via the coating.

2. The battery processing method according to claim 1, wherein: The coating has a conductive component. In the dipping step, the coating is placed on the Al terminal so that the conductive member and the Al terminal are electrically connected.

3. The battery processing method according to claim 2, wherein: The conductive member is a metal member.

4. The battery processing method according to claim 3, wherein: The material of the metal component is aluminum or aluminum alloy.

5. The battery processing method according to claim 3, wherein: The material of the metal component is iron or iron alloy.

6. The battery processing method according to claim 3, wherein: The material of the metal component is magnesium, magnesium alloy, zinc or zinc alloy.

7. The battery processing method according to claim 3, wherein: The metal member has a conductive resin portion on a surface on the Al terminal side.

8. The battery processing method according to claim 3, wherein: The metal member has a plated portion on a surface on the Al terminal side.

9. The battery processing method according to claim 2, wherein: The covering body further includes a first component, a second component, and a connecting component configured to connect the first component and the second component. In the dipping step, the first component and the second component are placed opposite each other with the Al terminal interposed therebetween, and the relative positions of the first component and the second component are fixed by the connecting component, so that the coating is arranged on the Al terminal, and the conductive component is arranged between the first component and the Al terminal.

10. The battery processing method according to claim 1, wherein: The covering body includes a first member, a second member, and a connecting member configured to connect the first member and the second member. At least one of the first component and the second component is a conductive component, In the dipping step, the first member and the second member are opposed to each other with the Al terminal interposed therebetween, and the relative positions of the first member and the second member are fixed by the connecting member, thereby arranging the covering body on the Al terminal.

11. The battery processing method according to claim 1, wherein: The covering body is a hollow component having a space portion. The hollow component is a conductive component, In the dipping step, the Al terminal is inserted into the space portion, thereby placing the coating body on the Al terminal.

12. The battery processing method according to claim 1, wherein: The covering body includes a first member and a pair of claw members respectively arranged on a pair of opposing sides of the first member. At least one of the first member and the claw member is a conductive member, In the dipping step, the Al terminal is fixed by the pair of claw members, whereby the covering body is arranged on the Al terminal.

13. The battery processing method according to claim 1, wherein: The battery includes an electrode body, an exterior body covering the electrode body, and the Al terminal electrically connected to the electrode body and partially exposed from the exterior body. In the dipping step, the covering body is arranged so as to cover at least a boundary between the Al terminal and the exterior body.

14. The battery processing method according to claim 1, wherein: The battery has a laminated exterior body.

15. The battery processing method according to claim 1, wherein: The battery is a solid-state battery.

16. A coating used in the battery processing method according to any one of claims 1 to 15, wherein: The coating body corresponds to any of the following coating bodies (i) to (iv), (i) the coating has a conductive member, (ii) the covering body includes a first member, a second member, and a connecting member configured to connect the first member and the second member, at least one of the first member and the second member being a conductive member; (iii) the covering body is a hollow member having a space portion, and the hollow member is a conductive member, (iv) The covering body includes a first member and a pair of claw members respectively arranged on a pair of opposing sides of the first member, and at least one of the first member and the claw members is a conductive member.

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