Method and apparatus for disassembling laminated battery

Abstract

To provide a method for disassembling a laminated battery more easily.SOLUTION: The disassembly method of the laminated battery 10 includes a preparation step and a heating step. In the preparation step, the laminated battery 10 including the laminate 20, the electrode body 30 enclosed in the laminate 20, and the electrolytic solution 40 enclosed in the laminate 20 is prepared. In the heating step, the laminated battery 10 is heated at least until the laminate 20 is opened.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method and apparatus for disassembling a laminated battery. [Background technology]

[0002] For example, Patent Document 1 discloses a method for disassembling a lithium-ion battery cell in which a stacked electrode, in which a positive electrode plate and a negative electrode plate are stacked with a separator interposed therebetween, is sealed in a laminate film exterior. In the method described in Patent Document 1, the lithium-ion battery cell is cut open at the edge of the laminate film, and then the laminate film is separated from the stacked electrode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-194749 Summary of the Invention [Problem to be solved by the invention]

[0004] In the method described in Patent Document 1, it is preferable that the cutting tool does not come into contact with the laminated electrode when cutting the laminate film. However, in many laminated batteries, the gap between the laminate and the electrode body is narrow, and it is not easy to cut the laminate without the cutting tool coming into contact with the electrode body. Here, we propose a method for more easily disassembling laminated batteries. We also propose a simpler device for disassembling laminated batteries. [Means for solving the problem]

[0005] The method for disassembling a laminated battery proposed here includes a preparation step of preparing a laminated battery comprising a laminate, an electrode body enclosed in the laminate, and an electrolyte enclosed in the laminate, and a heating step of heating the laminated battery at least until the laminate is opened.

[0006] The laminated battery disassembly device proposed here includes a chamber for accommodating a laminated battery comprising a laminate, an electrode body enclosed in the laminate, and an electrolyte enclosed in the laminate, and a heating device for heating the laminated battery in the chamber.

[0007] According to the above-described method and apparatus for disassembling a laminated battery, the laminate can be opened by the simple step of heating the laminated battery, making it easier to disassemble the laminated battery. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic vertical cross-sectional view of a laminated battery according to one embodiment. [Figure 2] FIG. 2 is a schematic diagram showing a part of the decomposition apparatus. [Figure 3] 1 is a flowchart showing the disassembly of a laminated battery. [Figure 4] FIG. 10 is a schematic diagram showing the configuration of a decomposition device according to another embodiment. [Figure 5] 10 is a flowchart showing another disassembly process for a laminated battery. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of a laminated battery disassembly device will be described below. It should be noted that the embodiment described here is not intended to limit the scope of the present invention. Furthermore, the drawings are schematic diagrams and do not necessarily faithfully reflect actual products. In the following, the same reference numerals will be used to designate components and parts that perform the same functions, and duplicate descriptions will be omitted or simplified as appropriate.

[0010] [Configuration of laminated battery] Fig. 1 is a schematic longitudinal cross-sectional view of a laminated battery 10 according to one embodiment. As shown in Fig. 1, the laminated battery 10 includes a laminated exterior material 20, an electrode assembly 30 enclosed in the laminated exterior material 20, an electrolyte solution 40 enclosed in the laminated exterior material 20, a positive electrode terminal 50, a negative electrode terminal 60, and a tab film 70 that serves as a sealant for the laminated exterior material 20.

[0011] Here, the electrode body 30 is a laminated electrode body in which a plurality of positive electrode sheets 31 and a plurality of negative electrode sheets 32 are stacked with separator sheets 33 interposed therebetween. However, the electrode body 30 may also be a wound electrode body in which the positive electrode sheets 31 and the negative electrode sheets 32 stacked with separator sheets 33 interposed therebetween are wound together.

[0012] The positive electrode sheet 31 is a member in which a positive electrode active material layer containing a positive electrode active material is formed on both sides of a metal foil of a predetermined width and thickness. The metal foil and the positive electrode active material are not particularly limited. Each positive electrode sheet 31 has a positive electrode tab 31a connected to a positive electrode terminal 50.

[0013] The negative electrode sheet 32 ​​is a member in which a negative electrode active material layer containing a negative electrode active material is formed on both sides of a metal foil of a predetermined width and thickness. The metal foil and the negative electrode active material are not particularly limited. Each negative electrode sheet 32 ​​has a negative electrode tab 32a connected to a negative electrode terminal 60.

[0014] For example, a porous resin sheet having required heat resistance and allowing the electrolyte to pass through is used as the separator sheet 33. There are no particular limitations on the material of the separator sheet 33. The separator sheet 33 is sandwiched between the positive electrode sheet 31 and the negative electrode sheet 32, and insulates the positive electrode sheet 31 from the negative electrode sheet 32.

[0015] The laminate exterior material 20 is formed of an insulating laminate film. The laminate exterior material 20 is configured in a bag shape and houses the electrode assembly 30. The edges of the laminate exterior material 20 sandwich and seal a positive electrode terminal 50 and a negative electrode terminal 60 connected to the electrode assembly 30. The positive electrode terminal 50 and the negative electrode terminal 60 each extend outside the laminate exterior material 20.

[0016] The tab film 70 is made of a thermoplastic resin. The tab film 70 is an example of a thermoplastic sealing material that seals the laminate exterior material 20. The tab film 70 is disposed between the edge of the laminate exterior material 20 on the positive electrode side and the positive electrode terminal 50, and between the edge of the laminate exterior material 20 on the negative electrode side and the negative electrode terminal 60. The tab film 70 is a thin film sheet. In terms of adhesiveness, polypropylene (PP) is a suitable thermoplastic resin. The positive electrode side tab film 70 is welded to the edge of the laminate exterior material 20 and the positive electrode terminal 50. The negative electrode side tab film 70 is welded to the edge of the laminate exterior material 20 and the negative electrode terminal 60. The tab film 70 thereby seals between the positive electrode terminal 50, the negative electrode terminal 60, and the laminate exterior material 20.

[0017] The electrolyte solution 40 is a solution in which an ionic substance is dissolved in a solvent, and mediates the transfer of charge between the positive electrode sheet 31 and the negative electrode sheet 32. For example, in the case of a lithium ion secondary battery, an organic solvent in which a lithium salt is dissolved is used as the electrolyte solution 40. In this case, the electrolyte solution 40 is, for example, a nonaqueous electrolyte solution in which LiPF6 is contained in a mixed solvent of ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC). However, various types of electrolyte solution 40 have been proposed, and there is no particular limitation. The solvent of the electrolyte solution 40 is partially vaporized by heating. The vaporized electrolyte solution 40 returns to a liquid when cooled.

[0018] [Configuration of decomposition equipment] 2 is a schematic diagram showing a portion of a decomposition device 100 (hereinafter also simply referred to as the decomposition device 100) for a laminated battery 10. As shown in FIG. 2, the decomposition device 100 includes a chamber 110 that houses the laminated battery 10, a heating device 120 that heats the laminated battery 10 in the chamber 110, and a substitution device 130 that substitutes the atmosphere in the chamber 110 with an inert gas G. Note that FIG. 2 only illustrates the configuration of the decomposition device 100 that opens the laminated outer casing 20 of the laminated battery 10. The decomposition device 100 may also include other configurations, such as a device that removes the electrode assembly 30 from the laminated outer casing 20.

[0019] As shown in Fig. 2, the chamber 110 is configured in the shape of a sealed box. The chamber 110 is provided with an openable and closable door 111. The laminated battery 10 is placed in the chamber 110 through the door 111. The chamber 110 is provided with an intake port 112 through which the inert gas G is supplied, and an exhaust port 113 through which the gas inside the chamber 110 is exhausted.

[0020] The heating device 120 includes a preheater 121 that heats the inert gas G before it is supplied to the chamber 110, and a panel heater 122 that heats and keeps the inert gas G warm in the chamber 110. In this embodiment, the heating device 120 heats the laminated battery 10 in the chamber 110 by heating the inert gas G. The inert gas G is, for example, nitrogen or argon. However, the type of inert gas G is not particularly limited. The preheater 121 is provided in an inlet pipe 132 that is connected to the intake port 112 and supplies the inert gas G. The panel heater 122 is provided in the chamber 110.

[0021] The heating device 120 includes a first temperature sensor 123 that measures the temperature of the inert gas G in the inlet pipe 132, and a second temperature sensor 124 that measures the temperature of the inert gas G in the chamber 110. The heating device 120 further includes a first control device 125 that controls the output of the preheater 121 based on the temperature measured by the first temperature sensor 123, and a second control device 126 that controls the output of the panel heater 122 based on the temperature measured by the second temperature sensor 124.

[0022] The substitution device 130 replaces the atmosphere in the chamber 110 with the inert gas G by exhausting the air in the chamber 110 through the exhaust port 113 and supplying the inert gas G to the chamber 110 through the intake port 112. The substitution device 130 includes a gas cylinder 131 storing the inert gas G, an inlet pipe 132 connecting the gas cylinder 131 to the intake port 112, an intake valve 133 provided on the inlet pipe 132, an outlet pipe 134 connected to the exhaust port 113, and an exhaust pump 135, an exhaust valve 136, and a filter 137 provided on the outlet pipe 134. The intake valve 133 opens when the inert gas G is introduced into the chamber 110 and is closed at other times. The exhaust valve 136 opens when the air or inert gas G is exhausted from the chamber 110 and is closed at other times. The exhaust pump 135 is driven when the air or inert gas G is exhausted from the chamber 110. Electrolyte 40 heated and vaporized by heating device 120 (hereinafter also referred to as vaporized electrolyte 40G) is collected by filter 137. Air and inert gas G are discharged from outlet pipe .

[0023] The above-described configurations of the chamber 110, the heating device 120, and the replacement device 130 are merely examples, and these configurations are not limited thereto. Various known configurations can be suitably used for the chamber 110, the heating device 120, and the replacement device 130.

[0024] [Laminated battery disassembly process] The following describes the process of disassembling a laminated battery 10 using the disassembly apparatus 100. FIG. 3 is a flowchart of the disassembly of a laminated battery 10. As shown in FIG. 3, in preparation step S01 of the process of disassembling a laminated battery 10, a laminated battery 10 is prepared. The laminated battery 10 is typically a used battery. When disassembling a laminated battery 10, the electrode assembly 30 is separated from the laminated exterior material 20 and the like in order to efficiently recover and reuse resources such as rare earths used in the electrode assembly 30.

[0025] In the accommodation step S02, the laminated battery 10 is accommodated in a sealed chamber 110. Specifically, the door 111 of the decomposition device 100 is opened, the laminated battery 10 is placed in the chamber 110, and the door 111 is closed. Note that although one laminated battery 10 is shown in FIG. 2, multiple laminated batteries 10 may be accommodated in the chamber 110 and processed simultaneously.

[0026] In the subsequent substitution step S03, the atmosphere in the chamber 110 is substituted with inert gas G. In the substitution step S03, the exhaust pump 135 is driven to exhaust the air in the chamber 110. After a predetermined time has passed, during which it is estimated that a certain amount of the air in the chamber 110 has been exhausted, inert gas G is supplied into the chamber 110, and the exhaust is stopped. In this embodiment, a preheating step S04, in which the inert gas G is heated in the inlet pipe 132, is performed in parallel with the substitution step S03. Therefore, high-temperature inert gas G is introduced into the chamber 110 from the beginning. For convenience of illustration, the preheating step S04 is illustrated after the substitution step S03 in FIG. 3.

[0027] Here, the temperature of the inert gas G to be introduced is equal to or higher than the melting point of the tab film 70, which is the sealing material of the laminate exterior material 20. For example, if the material of the tab film 70 is PP, the melting point of the tab film 70 is approximately 160°C. The temperature of the inert gas G to be introduced is, for example, equal to or higher than 160°C and equal to or lower than 300°C. However, the laminate exterior material 20 is opened by the internal pressure that increases due to the evaporation of the electrolyte 40. Therefore, the temperature of the inert gas G to be introduced may be lower than the melting point of the tab film 70, for example, a temperature lower than the melting point of the tab film 70 but equal to or higher than the softening temperature. When a predetermined time has elapsed, at which it is estimated that the chamber 110 is filled with the inert gas G, the supply of the inert gas G is stopped.

[0028] In the heating step S05, the laminated battery 10 is heated at least until the laminated exterior material 20 is opened. In this embodiment, heating of the laminated battery 10 is initiated by supplying heated inert gas G into the chamber 110. The inert gas G in the chamber 110 is maintained at a predetermined temperature (for example, the same temperature as the temperature of the inert gas G being introduced) by the panel heater 122. This heats the laminated battery 10. When the laminated battery 10 is heated, part of the electrolyte 40 vaporizes, and the internal pressure of the laminated exterior material 20 increases. In addition, the tab film 70 that seals the laminated exterior material 20 melts or softens due to the heat. As a result, the laminated exterior material 20 is opened.

[0029] In this embodiment, the heating step S05 ends when a predetermined time has elapsed during which it has been confirmed in advance that the laminated exterior material 20 has been reliably opened. "Heating the laminated battery 10 at least until the laminated exterior material 20 is opened" includes heating under such time management. However, it is also possible to monitor, for example, by a camera, whether the laminated exterior material 20 has been opened.

[0030] In an exhaust step S06, an exhaust pump 135 is driven to exhaust the inert gas G and vaporized electrolyte 40G from the chamber 110. In a removal step S07, the unsealed laminated battery 10 is removed from the chamber 110. Thereafter, the electrode body 30 is removed from the edge of the unsealed laminated exterior material 20, and rare earths and the like are recovered from the electrode body 30, but a description of these steps will be omitted.

[0031] [Effects of the embodiment] The following describes the effects that can be achieved by the method for disassembling the laminated battery 10 according to this embodiment.

[0032] The disassembly method for a laminated battery 10 according to this embodiment includes a preparation step S01 for preparing a laminated battery 10 including a laminated outer casing material 20, an electrode assembly 30 sealed in the laminated outer casing material 20, and an electrolyte solution 40 sealed in the laminated outer casing material 20, and a heating step S05 for heating the laminated battery 10 at least until the laminated outer casing material 20 is opened. This method allows the laminated outer casing material 20 to be opened through the simple step of heating the laminated battery 10. This makes it easier to disassemble the laminated battery 10. As described above, in conventional disassembly methods for laminated batteries, it is not easy to prevent a cutting tool from coming into contact with the electrode assembly when cutting the laminated outer casing material. However, cutting the laminated outer casing material so that the cutting tool may come into contact with the electrode assembly could result in a short circuit within the electrode assembly via the cutting tool. According to the method of this embodiment, a short circuit is unlikely to occur within the electrode body 30 because no cutting tool is used.

[0033] The disassembly method according to this embodiment includes a storage step S02 in which the laminated battery 10 is stored in a sealed chamber 110 before the heating step S05, and a substitution step S03 in which the atmosphere in the chamber 110 is substituted with an inert gas G after the storage step S02 and before the heating step S05. If the electrolyte 40 is in a high-temperature state and in air, there is a possibility that the electrolyte 40 will burn (react with oxygen in the air) if, for example, a short circuit occurs in the electrode assembly 30. In contrast, according to the method in which the atmosphere in the chamber 110 is substituted with the inert gas G, the atmosphere in the chamber 110 is an atmosphere of the inert gas G, and therefore the electrolyte 40 will not burn.

[0034] In this embodiment, the laminated exterior material 20 is sealed with a thermoplastic sealing material (tab film 70). In the heating step S05, the laminated battery 10 is heated to a temperature equal to or higher than the melting point of the tab film 70. According to this method, the tab film 70 melts in the heating step S05. Therefore, the laminated exterior material 20 can be reliably opened.

[0035] [Other embodiments] Although one embodiment of the proposed method for disassembling a laminated battery has been described above, the above embodiment is merely an example and the method can be implemented in other ways.

[0036] FIG. 4 is a schematic diagram showing the configuration of a decomposition apparatus 100 according to another embodiment. In the following description of the other embodiment, components that perform the same functions as those in the above-described embodiment are designated by the same reference numerals. As shown in FIG. 4, the decomposition apparatus 100 according to the other embodiment includes a chamber 110, a heating device 120, a pressure reducing device 140 that exhausts air from the chamber 110, and a collector 150 that collects and liquefies the vaporized electrolyte solution 40G. The decomposition apparatus 100 shown in FIG. 4 prevents combustion of the electrolyte solution 40 by heating the laminated battery 10 under a reduced pressure atmosphere. The decomposition apparatus 100 also collects the electrolyte solution 40 using the collector 150.

[0037] As shown in FIG. 4, the pressure reducing device 140 includes an exhaust pump 142 provided in the outlet pipe 141 and a pressure gauge 143 that measures the pressure inside the chamber 110. In this embodiment, the heating device 120 includes a heating table 127 that can heat an object even under reduced pressure. The heating table 127 is configured to heat itself to a high temperature, and the laminated battery 10 is heated by being placed on the heating table 127. However, the configuration of the heating device 120 for a reduced pressure atmosphere is not particularly limited. For example, the technology used in a vacuum furnace can be used for the heating device 120 for a reduced pressure atmosphere without any particular restrictions.

[0038] Collector 150 collects and liquefies vaporized electrolyte 40G that has been vaporized by heating by heater 120 and diffused within chamber 110. Collected electrolyte 40G is purified and reused. Collector 150 is connected to outlet piping 141. Collector 150 includes a collection container 151 and a cooling device 152. Vaporized electrolyte 40G discharged from chamber 110 is introduced into collection container 151. Cooling causes electrolyte 40 to liquefy and accumulate in collection container 151.

[0039] FIG. 5 is a flowchart of another disassembly process for the laminated battery 10. As shown in FIG. 5, in this embodiment, in a preparation step S11, the laminated battery 10 is prepared. In a storage step S12, the laminated battery 10 is stored in a sealed chamber 110. In a depressurization step S13, the air in the chamber 110 is exhausted using an exhaust pump 142, reducing the pressure inside the chamber 110. In a heating step S14, the laminated battery 10 is heated and opened. The heating step S14 is performed after the pressure gauge 143 detects that the pressure inside the chamber 110 has fallen below a predetermined pressure. Preferably, the pressure inside the chamber 110 continues to be reduced during the heating step S14. However, the pressure inside the chamber 110 does not necessarily need to be reduced while the heating step S14 is being performed.

[0040] In the heating step S14, the laminated battery 10 is heated at least until the laminated exterior material 20 is opened. In this embodiment, the heating step S14 ends after a predetermined time has elapsed during which it has been confirmed in advance that the laminated exterior material 20 has been reliably opened. By performing the heating step S14 in a reduced pressure atmosphere, it is possible to prevent the electrolyte solution 40 from burning.

[0041] The collecting step S15 is performed in parallel with the heating step S14. In the collecting step S15, the vaporized electrolyte solution 40G that has been vaporized in the heating step S14 and diffused within the chamber 110 is collected and liquefied. By the collecting step S15, at least a portion of the electrolyte solution 40G can be recovered and reused.

[0042] The above-described embodiments do not limit the present invention unless otherwise specified. For example, the heating step can be performed in air or in a location other than a sealed chamber. Furthermore, the technology disclosed herein can be modified in various ways. Each component and each process described herein can be omitted or combined as appropriate, unless a particular problem arises. This specification includes the disclosures described in the following sections.

[0043] Section 1: a preparation step of preparing a laminated battery including a laminate, an electrode assembly enclosed in the laminate, and an electrolyte enclosed in the laminate; and a heating step of heating the laminated battery at least until the laminate is opened. How to disassemble a laminated battery.

[0044] Section 2: a housing step of housing the laminated battery in a sealed chamber before the heating step; and a replacing step of replacing the atmosphere in the chamber with an inert gas after the containing step and before the heating step. Item 1. A method for disassembling a laminated battery according to item 1.

[0045] Section 3: a housing step of housing the laminated battery in a sealed chamber before the heating step; and a decompression step of discharging air from the chamber after the containing step and before the heating step. Item 1. A method for disassembling a laminated battery according to item 1.

[0046] Section 4: The method further includes a collecting step of collecting and liquefying the vaporized electrolyte solution that has been vaporized by the heating step and diffused into the chamber. Item 4. A method for disassembling a laminated battery according to item 3.

[0047] Section 5: the laminate is sealed with a thermoplastic sealant; In the heating step, the laminated battery is heated to a temperature equal to or higher than the melting point of the sealing material. Item 5. A method for disassembling a laminated battery according to any one of Items 1 to 4.

[0048] Item 6: a chamber containing a laminated battery including a laminate, an electrode assembly enclosed in the laminate, and an electrolyte enclosed in the laminate; a heating device for heating the laminated battery in the chamber; Laminated battery disassembly equipment.

[0049] Section 7: The apparatus further includes a replacement device that replaces the atmosphere in the chamber with an inert gas. Item 7. The laminated battery decomposition device according to item 6.

[0050] Section 8: Further comprising a pressure reducing device for discharging air from the chamber. Item 7. The laminated battery decomposition device according to item 6.

[0051] Section 9: The heating device further includes a collection device for collecting and liquefying the vaporized electrolyte solution that has been vaporized by heating with the heating device and diffused into the chamber. Item 9. The laminated battery decomposition device according to item 8.

[0052] Section 10: the laminate is sealed with a thermoplastic sealant; the heating device heats the laminated battery to a temperature equal to or higher than the melting point of the sealing material; Item 10. The laminated battery disassembly device according to any one of Items 6 to 9. [Explanation of symbols]

[0053] 10 Laminated battery 20 Laminate exterior materials (laminate) 30 Electrode body 31 Positive electrode sheet 31a Positive electrode tab 32 Negative electrode sheet 32a Negative electrode tab 33 Separator sheet 40 Electrolyte 40g vaporized electrolyte 50 Positive terminal 60 Negative terminal 70 Tab film (sealing material) 100 Decomposition equipment 110 Chamber 111 Door 112 Air intake 113 Exhaust port 120 Heating device 121 Preheater 122 Panel heater 123 First temperature sensor 124 Second temperature sensor 125 First control device 126 Second control device 127 Heating table 130 Replacement device 131 Gas Cylinder 132 Inlet piping 133 Intake valve 134 Outlet piping 135 Exhaust pump 136 Exhaust valve 137 filters 140 Pressure reducing device 141 Outlet piping 142 Exhaust pump 143 Pressure Gauge 150 Collection device 151 Collection vessel 152 Cooling device G Inert gas S01 Preparation Steps S02 Containment Step S03 Substitution step S04 Preheating step S05 Heating step S06 Exhaust step S07 Removal step S11 Preparation Steps S12 Containment Step S13 Decompression step S14 Heating step S15 Collection step

Claims

1. a preparation step of preparing a laminated battery including a laminate, an electrode assembly enclosed in the laminate, and an electrolyte enclosed in the laminate; and a heating step of heating the laminated battery at least until the laminate is opened. How to disassemble a laminated battery.

2. a housing step of housing the laminated battery in a sealed chamber before the heating step; and a replacing step of replacing the atmosphere in the chamber with an inert gas after the containing step and before the heating step. A method for disassembling the laminated battery according to claim 1.

3. a housing step of housing the laminated battery in a sealed chamber before the heating step; and a decompression step of discharging air from the chamber after the containing step and before the heating step. A method for disassembling the laminated battery according to claim 1.

4. The method further includes a collecting step of collecting and liquefying the vaporized electrolyte solution vaporized by the heating step and diffused into the chamber. A method for disassembling the laminated battery according to claim 3.

5. the laminate is sealed with a thermoplastic sealant; In the heating step, the laminated battery is heated to a temperature equal to or higher than the melting point of the sealing material. A method for disassembling the laminated battery according to claim 1.

6. a chamber containing a laminated battery including a laminate, an electrode assembly enclosed in the laminate, and an electrolyte enclosed in the laminate; a heating device for heating the laminated battery in the chamber; Laminated battery disassembly equipment.

7. The apparatus further includes a replacement device that replaces the atmosphere in the chamber with an inert gas. The laminated battery decomposition device according to claim 6.

8. Further comprising a pressure reducing device for discharging air from the chamber. The laminated battery decomposition device according to claim 6.

9. The heating device further includes a collection device for collecting and liquefying the vaporized electrolyte solution that has been vaporized by heating with the heating device and diffused into the chamber. The laminated battery decomposition device according to claim 8.

10. the laminate is sealed with a thermoplastic sealant; the heating device heats the laminated battery to a temperature equal to or higher than the melting point of the sealing material; The laminated battery decomposition device according to claim 6.

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