How to dispose of batteries

Abstract

To provide a processing method of a battery, in which it is difficult to damage an electrode body within an outer package body when a hole is opened through the outer package body.SOLUTION: According to the present invention, a processing method of a battery 100 that comprises: an outer package body 10; a gas exhaust valve 18 that is provided on the outer package body 10; and an electrode body 20 that is accommodated within the outer package body 10. Such the processing method comprises: a hole opening step of cleaving the gas exhaust valve 18 by applying force toward an external direction of the outer package body 10 for the gas exhaust valve 18 and opening a hole h through the outer package body 10; and a deactivation processing step of flowing deactivation processing liquid into the outer package body 10 from the hole h after the hole opening step and performing deactivation of the battery 100.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a method for treating a battery. [Background technology]

[0002] Conventionally, in order to reduce waste and effectively utilize resources, used batteries have been collected and recycled. In this regard, for example, Patent Document 1 describes a method in which a lithium-ion battery is disassembled, an electrode body is removed from an exterior body, and valuable metals such as Ni and Co are recovered as resources from the positive electrode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7120578 Summary of the Invention [Problem to be solved by the invention]

[0004] When dismantling a battery, in order to prevent the positive and negative electrodes from short-circuiting and catching fire, a deactivation process is usually performed by drilling a hole in the exterior body and pouring a deactivation treatment solution (e.g., water or salt water) into the interior of the exterior body to deactivate the electrode body. However, the internal structure of collected batteries varies depending on the manufacturer, model, battery capacity, etc., and if the battery has been used, the internal condition is unknown. Therefore, when drilling a hole in the exterior body, if a metal tool such as an awl is carelessly pierced into the exterior body, the electrode body inside the exterior body may be accidentally damaged, causing a short circuit between the positive and negative electrodes, and ultimately causing a fire.

[0005] The present invention has been made in consideration of the above circumstances, and its main object is to provide a battery processing method that is less likely to damage the electrode body inside the outer casing when holes are drilled in the outer casing. [Means for solving the problem]

[0006] The present invention provides a method for treating a battery including an exterior body, a gas exhaust valve provided in the exterior body, and an electrode assembly housed inside the exterior body. The method includes a hole making step of applying a force to the gas exhaust valve in a direction toward the outside of the exterior body to split the exterior body and make a hole in the exterior body, and a deactivation step of, after the hole making step, injecting a deactivation treatment solution into the interior of the exterior body through the hole to deactivate the battery.

[0007] The gas release valve is configured to break when the internal pressure of the exterior body becomes high, and is therefore the part of the exterior body that has the lowest strength and is the most easily broken. By applying a force toward the outside of the exterior body to the gas release valve, the gas release valve can be broken open and a hole can be made in the exterior body without using a metal tool such as an awl. Therefore, according to the present invention, it is possible to prevent the electrode body from being accidentally damaged by a metal tool, which would cause a short circuit between the positive and negative electrodes. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a schematic diagram of a battery according to an embodiment. [Diagram 2] FIG. 2 is a schematic vertical cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 3 is an enlarged view that illustrates a schematic view of the vicinity of the recess in FIG. [Figure 4] 4(A) and (B) are schematic diagrams of the battery in the hole-making step. [Diagram 5] FIG. 5 is a view of the second modified example corresponding to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, some preferred embodiments of the technology disclosed herein will be described with reference to the drawings. Note that matters other than those specifically mentioned in this specification and necessary for carrying out the present invention (for example, the general configuration and manufacturing process of a battery that do not characterize the present invention) can be understood as design matters of a person skilled in the art based on the prior art in the field. The present invention can be carried out based on the contents disclosed in this specification and the technical common sense in the field.

[0010] In this specification, the term "battery" refers to any power storage device capable of extracting electrical energy, and is a concept that includes primary batteries and secondary batteries. In addition, in this specification, the term "secondary battery" refers to any power storage device capable of repeated charging and discharging, and is a concept that includes so-called storage batteries (chemical batteries) such as lithium ion secondary batteries, and physical batteries such as lithium ion capacitors.

[0011] <Configuration of battery 100> Fig. 1 is a perspective view of a battery 100 that is the subject of the treatment disclosed herein. Fig. 2 is a schematic longitudinal sectional view taken along line II-II in Fig. 1. In the following description, the symbols L, R, F, Rr, U, and D in the drawings represent left, right, front, rear, top, and bottom. The symbols X and Y in the drawings represent the long side and short side directions of the battery 100, and the symbol Z represents the vertical direction. In the following drawings, the same symbols are used for members and parts that perform the same function, and duplicated descriptions may be omitted or simplified.

[0012] As shown in FIG. 2, the battery 100 includes an exterior body 10, a gas exhaust valve 18, an electrode body 20, a positive electrode terminal 30, a negative electrode terminal 40, a positive electrode current collector 50, a negative electrode current collector 60, a positive electrode internal insulating member 70, and a negative electrode internal insulating member 80. Although not shown, the battery 100 further includes an electrolyte. The battery 100 is a non-aqueous electrolyte secondary battery. The configuration of the battery 100 may be the same as that of a conventional battery, and is not particularly limited. In addition, the positive electrode internal insulating member 70 and the negative electrode internal insulating member 80 are not essential, and may be omitted in other embodiments.

[0013] The exterior body 10 is a housing that houses the electrode body 20. As shown in FIG. 1, the exterior body 10 here has a flat, bottomed rectangular parallelepiped (angular) outer shape. The material of the exterior body 10 may be the same as that conventionally used, and is not particularly limited. The exterior body 10 is preferably made of metal, and is composed of a lightweight metal material with good thermal conductivity, such as aluminum, an aluminum alloy, iron, or an iron alloy. Here, the exterior body 10 is made of aluminum.

[0014] As shown in Fig. 2, the exterior body 10 includes a case body 12 having an opening 12h, and a lid body (sealing plate) 14 that closes the opening 12h. The exterior body 10 is integrated by joining (e.g., welding) the lid body 14 to the periphery of the opening 12h of the case body 12. The joining of the lid body 14 can be performed by welding such as laser welding. The opening 12h of the case body 12 is hermetically sealed (sealed).

[0015] As shown in Fig. 1, the case body 12 includes a bottom wall 12a, a pair of long side walls 12b extending from the bottom wall 12a and facing each other, a pair of short side walls 12c extending from the bottom wall 12a and facing each other, and an opening 12h (see Fig. 2) facing the bottom wall 12a. The area of ​​the short side walls 12c is smaller than the area of ​​the long side walls 12b. The bottom wall 12a and the opening 12h are substantially rectangular.

[0016] The lid body 14 is a plate-shaped member that seals the opening 12h of the case body 12. As shown in FIG. 2, the lid body 14 is attached to the case body 12 so as to close the opening 12h. The lid body 14 is substantially rectangular in plan view. The lid body 14 is fitted into the opening 12h and faces the bottom wall 12a of the case body 12. The lid body 14 has an outer side surface 14a. The lid body 14 is provided with a liquid injection hole 15, a recess 17, and two terminal extraction holes 19. The lid body 14 with the recess 17 is formed, for example, by press-molding a flat metal member to make a recess in one portion.

[0017] The liquid injection hole 15 is for injecting an electrolyte solution after the lid body 14 is assembled to the case body 12. As shown in FIG. 2, the liquid injection hole 15 penetrates the lid body 14 in the vertical direction Z (in other words, the thickness direction of the lid body 14). The liquid injection hole 15 is a through hole. The liquid injection hole 15 is sealed by a liquid injection plug 16. The terminal withdrawal holes 19 are formed at both ends of the lid body 14 in the longitudinal direction Y. The terminal withdrawal holes 19 penetrate the lid body 14 in the vertical direction Z.

[0018] The recess 17 has a circular ring-shaped outer shape as shown in Fig. 1. The recess 17 is recessed in the vertical direction Z (in other words, in the thickness direction of the cover 14) from the outer surface 14a of the cover 14 as shown in Fig. 2. A gas exhaust valve 18 is disposed in the recess 17. Fig. 3 is an enlarged view showing a schematic view of the vicinity of the recess 17.

[0019] The gas exhaust valve 18 is configured to break when the internal pressure of the exterior body 10 rises above a predetermined operating pressure, thereby discharging the gas in the exterior body 10 to the outside. The operating pressure of the gas exhaust valve 18 is typically 0.1 to 10 MPa, for example, 0.3 to 5 MPa, or 1 to 3 MPa. The gas exhaust valve 18 is provided in the exterior body 10. As shown in FIG. 3, the gas exhaust valve 18 constitutes the lower surface of the recess 17 here, and is provided integrally with the lid body 14. Therefore, the gas exhaust valve 18 is made of the same type of material as the lid body 14, for example, a metal material such as aluminum, an aluminum alloy, iron, or an iron alloy. The gas exhaust valve 18 is made of aluminum here. The gas exhaust valve 18 has a thickness tb. The gas exhaust valve 18 is formed to be thinner than the thickness ta of the plate-shaped lid body 14.

[0020] In this embodiment, gas exhaust valve 18 is integral with cover 14, but may be separate from cover 14. For example, cover 14 may have a gas exhaust hole (through hole) penetrating through cover 14 in the thickness direction instead of recess 17, and gas exhaust valve 18 may be attached to cover 14 by, for example, welding so as to close the gas exhaust hole. In this case, gas exhaust valve 18 may be made of a material different from that of cover 14.

[0021] Here, the gas exhaust valve 18 has a flat portion 18a and a cutout portion (notch portion, groove portion) 18b. The flat portion 18a is provided in the center including the center M of the gas exhaust valve 18 in a plan view. The flat portion 18a has a flat surface, does not have a cutout portion or the like, and is a continuous surface. When the gas exhaust valve 18 has the flat portion 18a in the center, there is an advantage that the technology disclosed herein can be easily applied to the processing method described later. The cutout portion 18b is substantially annular here and is provided along the outer edge of the recess 17. In other words, the cutout portion 18b is provided along the outer periphery of the flat portion 18a. The cutout portion 18b is a fragile portion of the gas exhaust valve 18 that has particularly low strength. For this reason, in this embodiment, the gas exhaust valve 18 is ruptured along the substantially annular cutout portion 18b. If the gas exhaust valve 18 has the cutout portion 18b, there is an advantage that metal foreign matter such as metal fragments is less likely to be generated when the gas exhaust valve 18 is cleaved in a processing method described below.

[0022] The electrode body 20 is accommodated inside the exterior body 10. The electrode body 20 has a positive electrode and a negative electrode. The electrode body 20 is a wound electrode body in which a strip-shaped positive electrode and a strip-shaped negative electrode are stacked with a strip-shaped separator interposed therebetween and wound in the longitudinal direction around a winding axis. The electrode body 20 has a flat outer shape. However, the electrode body 20 may be a laminated electrode body in which a rectangular positive electrode and a rectangular negative electrode are stacked in an insulated state. The electrode body 20 is accommodated inside the exterior body 10 in this case with the winding axis oriented approximately parallel to the long side direction Y. However, the electrode body 20 may be accommodated inside the exterior body 10 with the winding axis oriented approximately parallel to the vertical direction Z. In addition, the number of electrode bodies 20 accommodated in one exterior body 10 may be one, or two or more (plural).

[0023] The positive electrode has a positive electrode current collector and a positive electrode composite layer fixed on the positive electrode current collector. The positive electrode current collector is made of a conductive metal such as aluminum, an aluminum alloy, nickel, or stainless steel. The positive electrode current collector is made of aluminum in this embodiment. The positive electrode composite layer typically contains a positive electrode active material (e.g., lithium transition metal composite oxide) capable of reversibly absorbing and releasing charge carriers and a binder (e.g., polyvinylidene fluoride (PVdF)).

[0024] The negative electrode has a negative electrode current collector and a negative electrode mixture layer fixed on the negative electrode current collector. The negative electrode current collector is made of a conductive metal such as copper, a copper alloy, nickel, or stainless steel. The negative electrode current collector is made of copper in this embodiment. The negative electrode mixture layer typically contains a negative electrode active material (e.g., a carbon material such as graphite) that can reversibly store and release charge carriers, and a binder (e.g., styrene butadiene rubber (SBR) or carboxymethyl cellulose (CMC)).

[0025] A part of the positive electrode current collector on which the positive electrode composite layer is not formed (positive electrode tab 23) is exposed at one end (left end in FIG. 2) of the electrode body 20 in the long side direction Y. The lower end of the positive electrode current collector 50 is connected to the positive electrode tab 23. Moreover, a part of the negative electrode current collector on which the negative electrode composite layer is not formed (negative electrode tab 25) is exposed at the other end (right end in FIG. 2) of the electrode body 20 in the long side direction Y. The lower end of the negative electrode current collector 60 is connected to the negative electrode tab 25.

[0026] The electrolytic solution here is a nonaqueous liquid electrolyte (nonaqueous electrolytic solution) containing a nonaqueous solvent and a supporting salt. The nonaqueous solvent contains, for example, carbonates such as ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC). The supporting salt is, for example, a fluorine-containing lithium salt such as LiPF6. However, the electrolytic solution may be in a solid state (solid electrolyte) and integrated with the electrode body 20.

[0027] As shown in Figs. 1 and 2, the positive electrode terminal 30 is disposed at one end (the left end in Figs. 1 and 2) of the lid body 14 in the longitudinal direction Y. As shown in Fig. 2, the positive electrode terminal 30 is electrically connected to the positive electrode of the electrode body 20 through the positive electrode current collector 50 inside the exterior body 10. The positive electrode terminal 30 extends from the inside to the outside of the lid body 14 through the terminal pull-out hole 19. The positive electrode terminal 30 is made of a metal such as aluminum, an aluminum alloy, nickel, or stainless steel. Here, the positive electrode terminal 30 is made of aluminum. The positive electrode terminal 30 is insulated from the lid body 14 by a positive electrode internal insulating member 70 and a gasket 90.

[0028] A plate-shaped positive electrode external conductive member 32 is fixed on the positive electrode terminal 30. The positive electrode external conductive member 32 is a member that is connected to other batteries or external devices via a bus bar or the like. The positive electrode external conductive member 32 is attached to the lid body 14 in a state insulated from the lid body 14 by an external insulating member 92. The positive electrode external conductive member 32 is made of a metal such as aluminum, an aluminum alloy, nickel, or stainless steel. Here, the positive electrode external conductive member 32 is made of aluminum.

[0029] As shown in Figs. 1 and 2, the negative electrode terminal 40 is disposed at the other end (the right end in Figs. 1 and 2) of the lid 14 in the longitudinal direction Y. As shown in Fig. 2, the negative electrode terminal 40 is electrically connected to the negative electrode of the electrode body 20 through the negative electrode current collector 60 inside the exterior body 10. The negative electrode terminal 40 extends from the inside to the outside of the lid 14 through the terminal pull-out hole 19. The negative electrode terminal 40 is made of a metal such as copper, a copper alloy, nickel, or stainless steel. Here, the negative electrode terminal 40 is made of copper. The negative electrode terminal 40 is insulated from the lid 14 by a negative electrode internal insulating member 80 and a gasket 90.

[0030] A plate-shaped negative electrode external conductive member 42 is fixed on the negative electrode terminal 40. The negative electrode external conductive member 42 is a member that is connected to other batteries or external devices via a bus bar or the like. The negative electrode external conductive member 42 is attached to the lid body 14 in a state insulated from the lid body 14 by an external insulating member 92. The negative electrode external conductive member 42 is made of a metal such as copper, a copper alloy, nickel, or stainless steel. Here, the negative electrode external conductive member 42 is made of copper.

[0031] The positive electrode current collecting part 50 constitutes a conductive path that electrically connects the positive electrode tab 23 and the positive electrode terminal 30. The positive electrode current collecting part 50 may be made of the same metal type as the positive electrode current collector, for example, a conductive metal such as aluminum, an aluminum alloy, nickel, or stainless steel. Here, the positive electrode current collecting part 50 is substantially L-shaped. The positive electrode current collecting part 50 extends along the inner surface of the lid 14 and has a positive electrode first current collecting part that is connected to the positive electrode terminal 30, and a positive electrode second current collecting part that extends along the short side wall 12c of the case body 12 and is connected to the positive electrode tab 23.

[0032] The negative electrode current collecting part 60 constitutes a conductive path that electrically connects the negative electrode tab 25 and the negative electrode terminal 40. The negative electrode current collecting part 60 may be made of the same metal type as the negative electrode current collector, for example, a conductive metal such as copper, a copper alloy, nickel, or stainless steel. Here, the negative electrode current collecting part 60 is substantially L-shaped. The negative electrode current collecting part 60 extends along the inner surface of the lid 14 and has a negative electrode first current collecting part that is connected to the negative electrode terminal 40, and a negative electrode second current collecting part that extends along the short side wall 12c of the case body 12 and is connected to the negative electrode tab 25.

[0033] The positive electrode internal insulating member 70 is provided between the inner surface of the lid body 14 and the electrode body 20. The positive electrode internal insulating member 70 is a member that insulates the lid body 14 and the positive electrode current collecting part 50 (specifically, the positive electrode first current collecting part) inside the exterior body 10. The positive electrode internal insulating member 70 is made of, for example, a resin material that has resistance to the electrolyte used and electrical insulation properties and is elastically deformable. The positive electrode internal insulating member 70 is preferably made of, for example, a polyolefin resin such as polypropylene (PP), a fluorinated resin such as tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA), polyphenylene sulfide (PPS), or the like.

[0034] 2, the positive electrode internal insulating member 70 here has a base portion 70a and a protruding portion 70b. The base portion 70a is disposed between the lid body 14 and the positive electrode first current collecting portion, and extends along the inner surface of the lid body 14. The protruding portion 70b protrudes toward the electrode body 20 side beyond the base portion 70a.

[0035] As shown in FIG. 2, the negative electrode internal insulating member 80 is disposed symmetrically with the positive electrode internal insulating member 70 with respect to the long side direction Y of the electrode body 20. The specific configuration of the negative electrode internal insulating member 80 may be similar to that of the positive electrode internal insulating member 70. The negative electrode internal insulating member 80 is a member that insulates the lid body 14 and the negative electrode current collecting part 60 (specifically, the negative electrode first current collecting part) inside the exterior body 10. Here, like the positive electrode internal insulating member 70, the negative electrode internal insulating member 80 has a base part 80a disposed between the lid body 14 and the negative electrode first current collecting part, and a protruding part 80b protruding toward the electrode body 20 side from the base part 80a.

[0036] <How to dispose of the battery 100> The treatment method of this embodiment is a treatment method (deactivation treatment method) for batteries 100 collected from the market. The collected batteries 100 may be in an unused state or in a used state. The collected batteries 100 may be in a state where they cannot be used and cannot be discharged due to overcharging, overdischarging, or the like.

[0037] The processing method of this embodiment includes a voltage checking step (step S1), a discharge treatment step (step S2), a hole making step (step S3), and a deactivation treatment step (step S4) in this order. However, the voltage checking step (step S1) and the discharge treatment step (step S2) are not essential and may be omitted in other embodiments. Furthermore, other steps may be included at any stage. Figures 4(A) and (B) are schematic diagrams of the battery 100 in the hole making step (step S3).

[0038] In the voltage confirmation step (step S1), the collected battery 100 is connected to a charge / discharge device to confirm the voltage (voltage at the time of collection). In this step, the battery 100 (specifically, the exterior body 10) is typically in a normal position with the lid body 14 located directly above the vertical direction Z and the long side wall 12b and the short side wall 12c aligned with the vertical direction Z. However, the battery 100 may be in a position other than the normal position.

[0039] The collected batteries 100 often have a voltage. If the collected batteries 100 have a voltage, it is preferable to perform a discharge process prior to the deactivation process (step S4). For this reason, the process proceeds to step S2. However, if the collected batteries 100 do not have a voltage or are in a state where discharge is not possible, the discharge process can be omitted. For this reason, the process may proceed to step S3, omitting step S2.

[0040] In the discharge treatment step (step S2), the battery 100 is forced to discharge, lowering the voltage of the battery 100. This improves the safety of the work in the subsequent steps. For example, it is possible to reduce the risk of a large amount of gas being generated in the deactivation treatment step (step S4). Note that in this step, the battery 100 (specifically, the exterior body 10) is typically in a normal position. However, it may be in a position other than the normal position.

[0041] The discharge process can be performed in the same manner as in the past. The collected batteries 100 often have variations in the state of charge (SOC). Therefore, it is preferable to appropriately adjust the discharge conditions in this step, such as the discharge rate or ultimate voltage in CC discharge (constant current discharge) and the holding voltage or holding time in CV discharge (constant voltage discharge), depending on the voltage of the battery 100 at the time of collection. From the viewpoint of improving the safety of the work after the next step, it is preferable to make the residual voltage as small as possible. Therefore, it is preferable to perform the discharge process until the residual voltage of the battery 100 becomes approximately 0.5 V or less, for example, approximately 0 V. Then, the process proceeds to step S3.

[0042] In the hole making step (step S3), as shown in FIG. 4(B), a hole h is made in the exterior body 10 to allow liquid to flow therein. The hole h is typically large enough to allow liquid to flow therein but not large enough to allow the electrode body 20 to be removed. In this embodiment, the hole h is made at the position of the gas exhaust valve 18 provided in the lid 14. More specifically, the hole h is made in the exterior body 10 by forcibly splitting the gas exhaust valve 18. Therefore, the size of the hole h is typically the same as or smaller than the gas exhaust valve 18. However, it may be larger than the gas exhaust valve 18.

[0043] As described above, the gas release valve 18 is configured to rupture when the internal pressure of the exterior body 10 rises above a predetermined operating pressure. For this reason, the hole h can be easily opened by applying a force toward the outside of the exterior body 10, preferably a force equivalent to the operating pressure (for example, a force with the same vector as the internal pressure rise), to the gas release valve 18. Furthermore, by opening the hole h in this manner, there is no need to use a metal tool such as a drill or an awl, and therefore it is possible to prevent the electrode body from being accidentally damaged by a metal tool, thereby causing a short circuit between the positive and negative electrodes.

[0044] In this embodiment, the adsorption device 200 is used to open the gas exhaust valve 18. Specifically, first, the adsorption device 200 (see FIG. 4(A)) is prepared. The adsorption device 200 may have the same configuration as that of a conventionally used device, and is not particularly limited. As shown in FIG. 4(A), the adsorption device 200 has, for example, an adsorption unit 210 and a moving mechanism 220. The adsorption unit 210 is provided on a surface facing the gas exhaust valve 18. The adsorption unit 210 is flat here. Although not shown, a plurality of suction holes for adsorbing the gas exhaust valve 18 (specifically, the flat surface portion 18a) are provided on the lower surface of the adsorption unit 210. The suction holes are provided inside the outer dimensions of the gas exhaust valve 18 (preferably the flat surface portion 18a). The suction holes are connected to a vacuum source (e.g., a vacuum pump) not shown. The adsorption device 200 is controlled to adsorb and release adsorption by controlling the on / off of the vacuum source. The movement mechanism 220 moves (here, lowers and raises) the adsorption unit 210 toward the side approaching the gas exhaust valve 18 and toward the side away from the gas exhaust valve 18. The movement mechanism 220 is, for example, an up-down cylinder.

[0045] In this embodiment, the adsorption part 210 is then lowered by the moving mechanism 220, and the adsorption part 210 is brought into contact with the gas exhaust valve 18 (specifically, the flat surface 18a). In this state, the vacuum source is turned on to draw a vacuum, so that the gas exhaust valve 18 is adsorbed to the adsorption part 210. Preferably, the gas exhaust valve 18 is vacuum-adsorbed. At this time, if the gas exhaust valve 18 has the flat surface 18a in the center, the gas exhaust valve 18 can be adsorbed relatively more strongly than, for example, a case in which a notch or the like is formed in the center or the surface of the center is curved. Also, the wider the flat surface 18a, the more favorably the adsorption force can be ensured.

[0046] Next, as shown by the arrow in FIG. 4(A), the adsorption unit 210 is raised by the moving mechanism 220. As a result, the gas exhaust valve 18 is raised together with the adsorption unit 210, and a force toward the outside of the exterior body 10 is applied to the gas exhaust valve 18. The gas exhaust valve 18 is typically ruptured when a force equal to or greater than the operating pressure (a force with the same vector as the internal pressure increase) is applied. In this way, as shown in FIG. 4(B), the gas exhaust valve 18 is adsorbed and removed by the adsorption unit 210, and a hole h is opened in the exterior body 10. In this embodiment, by adsorbing and removing the gas exhaust valve 18, it is possible to prevent metal foreign matter such as metal pieces generated by the rupture from entering the interior of the exterior body 10 through the hole h. In addition, if the gas exhaust valve 18 has a notch 18b at this time, the gas exhaust valve 18 is ruptured along the notch 18b, so that metal foreign matter such as metal pieces is less likely to be generated. Therefore, short-circuiting between the positive and negative electrodes can be suppressed to a higher level, and the risk of fire is reduced.

[0047] The atmosphere when the gas release valve 18 is opened is preferably an inert gas atmosphere. When the battery 100 has a liquid electrolyte (non-aqueous electrolyte), the battery 100 (specifically, the exterior body 10) is typically in a normal position in this step, as shown in Figs. 4(A) and (B). This prevents the non-aqueous electrolyte from spilling out of the exterior body 10 when the hole h is opened. However, when the battery 100 has a solid electrolyte or when the method of the second modified example described later is adopted, the battery 100 may be in a position other than the normal position. Then, the process proceeds to step S4.

[0048] In the deactivation process (step S4), a conductive liquid (deactivation liquid) such as water or saline is introduced into the exterior body 10 through a hole h provided at the position of the gas exhaust valve 18 of the exterior body 10 to deactivate the battery 100. The method of introducing the deactivation liquid into the interior of the exterior body 10 may be, for example, to inject the deactivation liquid into the interior of the exterior body 10 through the hole h, or to immerse the entire exterior body 10 in the deactivation liquid. In this process, the battery 100 (specifically, the exterior body 10) is typically in a normal position. However, the battery 100 may be in a position other than the normal position, for example, when the entire exterior body 10 is immersed in the deactivation liquid.

[0049] The deactivation treatment (typically salt water treatment) can be carried out in the same manner as in the past. The conditions of the deactivation treatment, such as the treatment time, the concentration of the treatment agent (salt (sodium chloride), etc.), the electrical conductivity of the deactivation treatment solution, etc., can be appropriately adjusted depending on the residual voltage of the battery 100. This allows the battery 100 to be completely discharged and deactivated.

[0050] As described above, after the hole h is opened in the exterior body 10 and the battery 100 is deactivated, the exterior body 10 can be cut, for example, along the opening 12h to separate it into the case body 12 and the lid body 14. The case body 12 can be recycled as aluminum. In addition, the electrode body 20 can be removed from the case body 12 and separated into a composite material (so-called black mass) and a current collector, and valuable metals can be recovered from the electrode body 20 by a conventionally known method. For example, rare metals such as lithium (Li) and transition metals (e.g., Ni, Co, Mn) can be recovered.

[0051] Although the embodiment of the present invention has been described above, the above embodiment is merely an example. The present invention can be implemented in various other forms. The present invention can be implemented based on the contents disclosed in this specification and the technical common sense in the field. The technology described in the claims includes various modifications and changes of the above-exemplified embodiment. For example, it is possible to replace a part of the above-mentioned embodiment with another modified form, and it is also possible to add another modified form to the above-mentioned embodiment. Furthermore, if the technical feature is not described as essential, it is also possible to delete it as appropriate.

[0052] For example, in the above embodiment, the gas exhaust valve 18 is provided in the cover 14. However, this is not limited thereto. In a modified example, the gas exhaust valve 18 may be provided in a portion other than the cover 14, for example, the long side wall 12b or the short side wall 12c of the case body 12. In the above embodiment, the gas exhaust valve 18 has a flat portion 18a in the central portion including the center M. However, this is not limited thereto. In a modified example, the central portion of the gas exhaust valve 18 may be provided with a cutout portion (for example, linear (I-shaped) or Y-shaped in a plan view) that passes through the center M. In addition, the central portion of the gas exhaust valve 18 may be, for example, a curved surface or an uneven surface.

[0053] For example, in the above embodiment, in the hole making step (step S3), the adsorption device 200 is used to adsorb and remove the gas release valve 18 with the adsorption unit 210, thereby opening a hole h in the exterior body 10. However, this is not limited to this. For example, as in the above modified example, if a notch or the like is formed in the center of the gas release valve 18 or the surface of the center is curved, it may be difficult for the adsorption unit 210 to adsorb the gas release valve 18, or the desired adsorption force may not be obtained. In such a case, the following method can be preferably adopted.

[0054] (First Modification) In the first modification, a gripping member is prepared instead of the adsorption device 200. The gripping member is, for example, a rod-shaped disposable member. From the viewpoint of recycling, the gripping member is preferably made of the same material as the gas exhaust valve 18. When the gas exhaust valve 18 is made of aluminum, the gripping member is also preferably made of aluminum.

[0055] In the first modified example, first, the end of the gripping member is bonded or welded to the gas release valve 18 to integrate them. If the gas release valve 18 and the gripping member are made of metal, resistance welding, laser welding, electron beam welding, or other welding is preferable. If the gas release valve 18 and / or the gripping member are made of resin, adhesion with an adhesive or welding such as ultrasonic welding is preferable.

[0056] Next, the gripping member is gripped by a moving mechanism such as an up-down cylinder, and the gripping member is pulled up to apply a force to the gas release valve 18 toward the outside of the exterior body 10. Alternatively, an operator may grab and pull the gripping member. The gas release valve 18 can also be opened by such a method.

[0057] (Second Modification) In the second modification, a pressure adjusting device 300 is prepared instead of the adsorption device 200. The pressure adjusting device 300 may have the same configuration as that of a conventionally used device, and is not particularly limited. FIG. 5 is a view corresponding to FIG. 4(A) in the second modification. As shown in FIG. 5, the pressure adjusting device 300 has a chamber 310 and a pressure adjusting section 320 that adjusts the pressure in the chamber 310. The chamber 310 has a cylindrical shape and an inner diameter larger than the gas exhaust valve 18 and smaller than the width (length in the short side direction X) of the lid 14. The chamber 310 has a size that can cover the gas exhaust valve 18. However, the chamber 310 may have a size that can accommodate one or more batteries 100 as they are.

[0058] The pressure adjusting unit 320 has a structure in which, for example, a gas supply source (e.g., an inert gas tank) is connected to one of the branched flow paths, a vacuum source (e.g., a vacuum pump) is connected to the other flow path, and a three-way valve is disposed at the branch point. The pressure adjusting unit 320 is configured to reduce the pressure inside the chamber 310 by switching the three-way valve so that the chamber 310 communicates with the vacuum source, and to depressurize (pressurize) the chamber 310 by switching the three-way valve so that the chamber 310 communicates with the gas supply source.

[0059] In the second modified example, first, as shown in FIG. 5, the chamber 310 is placed so as to cover the gas exhaust valve 18, and is brought into close contact with the cover 14 (the peripheral portion of the gas exhaust valve 18). This allows a sealed space to be formed near the gas exhaust valve 18. Next, the three-way valve is switched to reduce the pressure inside the sealed space at least once (to change the pressure inside the sealed space). This applies a force toward the outside of the exterior body 10 to the gas exhaust valve 18. However, according to the study by the present inventor, it is difficult to apply a force of more than the operating pressure to the gas exhaust valve 18 by reducing the pressure inside the sealed space, and there are cases where the gas exhaust valve 18 does not break open with only one decompression operation. Therefore, if the gas exhaust valve 18 does not break open, the three-way valve is switched to once release the pressure inside the chamber 310 and return it to atmospheric pressure, and then the sealed space is decompressed again. This operation (pressurization and decompression) is repeated multiple times to cause fatigue failure of the gas exhaust valve 18, and the gas exhaust valve 18 can be broken open.

[0060] In the second modified example, as shown in Fig. 5, it is preferable to have the battery 100 (specifically, the exterior body 10) in an inverted position with the lid 14 facing directly below in the vertical direction Z. As a result, when the gas release valve 18 is split open, the hole h (not shown in Fig. 5, see Fig. 4(B)) faces directly below in the vertical direction Z. This makes it possible to prevent metal foreign matter such as metal pieces generated by the split from entering the interior of the exterior body 10 through the hole h, compared to when the gas release valve 18 is split open with the battery 10 in the normal position.

[0061] As described above, specific aspects of the technology disclosed herein include those described in the following sections. Item 1: A method for treating a battery comprising an exterior body, a gas exhaust valve provided in the exterior body, and an electrode body contained inside the exterior body, the method including: a hole-making step of applying a force toward the outside of the exterior body to the gas exhaust valve to cleave the gas exhaust valve and make a hole in the exterior body; and a deactivation step of, after the hole-making step, injecting a deactivation treatment solution into the interior of the exterior body through the hole to deactivate the battery. Item 2: The processing method according to item 1, wherein in the hole-making step, an adsorption device having an adsorption section is used, and the gas exhaust valve is adsorbed to the adsorption section and then pulled up, thereby cleaving the gas exhaust valve. Item 3: The processing method according to item 1, wherein in the hole making step, a gripping member is adhered or welded to the gas release valve, and then the gas release valve is opened by lifting up the gripping member. Item 4: The processing method according to item 1, wherein in the hole-making step, a sealed space is formed surrounding the gas exhaust valve, and the gas exhaust valve is opened by changing the pressure in the sealed space. Item 5: The processing method according to any one of Items 1 to 4, wherein the gas exhaust valve has a flat portion in the center. Item 6: The method according to any one of Items 1 to 5, wherein the gas exhaust valve has a notch. Item 7: The method according to any one of items 1 to 6, further comprising a discharge treatment step of discharging the battery before the hole-forming step. [Explanation of symbols]

[0062] 10 Exterior body 12 Case body 14 Lid 18 Gas exhaust valve 18a Flat part 18b Cutout 20 Electrode body 100 batteries 200 Adsorption device 210 Adsorption part 220 Moving mechanism 300 Pressure Regulator 310 Chamber 320 Pressure Regulator

Claims

1. A method for treating a battery including an exterior body, a gas exhaust valve provided in the exterior body, and an electrode assembly housed inside the exterior body, comprising the steps of: a hole making step of applying a force to the gas release valve in an outward direction of the exterior body to split the gas release valve and make a hole in the exterior body; a deactivation treatment step of injecting a deactivation treatment solution into the exterior body through the hole after the hole opening step, thereby deactivating the battery; Including, In the hole making step, an adsorption device having an adsorption part is used, and the gas exhaust valve is adsorbed to the adsorption part and then pulled up, thereby opening the gas exhaust valve. How to dispose of batteries.

2. A method for treating a battery including an exterior body, a gas exhaust valve provided in the exterior body, and an electrode assembly housed inside the exterior body, comprising the steps of: a hole making step of applying a force to the gas release valve in an outward direction of the exterior body to split the gas release valve and make a hole in the exterior body; a deactivation treatment step of injecting a deactivation treatment solution into the exterior body through the hole after the hole opening step, thereby deactivating the battery; Including, In the hole making step, a gripping member is adhered or welded to the gas release valve, and then the gripping member is pulled up to open the gas release valve. How to dispose of batteries.

3. The gas exhaust valve has a flat portion in the center.

3. The method according to claim 1 or 2.

4. The gas exhaust valve has a notch.

3. The method according to claim 1 or 2.

5. A discharge treatment step of discharging the battery is included before the hole drilling step.

3. The method according to claim 1 or 2.

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