A method for disassembling a battery module

Abstract

The application discloses a kind of battery module disassembly methods, comprising the following steps: (1) the positive and negative pole connecting piece of battery module to be disassembled is milled, and the milled battery module is obtained;The milled battery module is frozen, and the frozen battery module is obtained;(2) organic solvent is reduced pressure and heated, and organic vapor is obtained;Organic solvent is one or more of n-butanol, n-pentanol, phenethyl alcohol, dimethyl hexanol;(3) the frozen battery module is placed in airtight reaction tank, and organic vapor is introduced into airtight reaction tank for organic vapor treatment, and the battery module after organic vapor treatment is obtained;(4) the battery module after organic vapor treatment is disassembled, and the monomer fixed glue in the battery module after organic vapor treatment is removed, and the battery monomer is obtained.The application can reduce the disassembly difficulty of battery module.

Description

Technical Field

[0001] This invention belongs to the field of waste battery recycling, and specifically relates to a method for disassembling battery modules. Background Technology

[0002] Lithium-ion batteries have advantages such as high energy density, low voltage, wide operating temperature range, and long lifespan, and have been widely used in the new energy vehicle industry. With the large-scale application of power batteries, my country will face a wave of retired power batteries, making the efficient reuse of these batteries an urgent issue. Traditional battery packs consist of multiple battery modules, with individual cells within each module bonded together using adhesives such as polyurethane structural adhesives. Directly disassembling these cells can easily cause damage and is not conducive to reuse.

[0003] CN 113523746 A discloses a method for disassembling a battery pack. This method involves applying a desiccant and then transferring the battery pack to a low-temperature environment to weaken the adhesive strength of the structural adhesive and prevent damage during disassembly. However, the desiccant has complex components, high cost, and significant harm to human health and the environment, hindering large-scale industrial production. Freezing followed by desiccant removal is currently the most common pretreatment method before disassembly. However, during the rewarming process, moisture in the air condenses on the surface of the individual cells, forming a discharge circuit and rendering the cells unusable. This phenomenon is more pronounced in humid southern regions, causing the cells to lose their value for reuse and making it difficult to utilize retired batteries more economically. Furthermore, when the temperature rises to a certain level, the brittleness of the adhesive decreases while its toughness increases, leading to re-adhesion and increasing the difficulty of disassembly, making it impossible to effectively achieve non-destructive disassembly.

[0004] CN 112687974 A discloses a chemical dismantling method for battery adhesive modules. This method involves immersing the battery adhesive module in a dismantling tank with a composite N-methylpyrrolidone organic solvent, subjecting it to omnidirectional vibration, and then filtering it three times. The battery and functional components filtered out in the first filtration are cleaned and dried for recycling. The functional adhesive particles filtered out in the second filtration are dried, pyrolyzed, ground, extracted, and reduced to metal compounds for recycling; the remaining solids are treated as solid waste. Fine impurities filtered out in the third filtration are dried and become solid waste. This patent uses organic solvent immersion, which has the disadvantage of using a large amount of organic solvent. Summary of the Invention

[0005] To address the problems in the existing technology, the present invention provides a method for disassembling battery modules that can reduce the difficulty of disassembly.

[0006] The present invention adopts the following technical solution:

[0007] A method for disassembling a battery module includes the following steps:

[0008] (1) Mill the positive and negative terminal connecting pieces of the battery module to be disassembled to obtain the milled battery module; freeze the milled battery module to obtain the frozen battery module.

[0009] (2) The organic solvent is heated under reduced pressure to obtain organic vapor; the organic solvent is one or more of n-butanol, n-pentanol, phenethyl alcohol, and dimethylhexanol;

[0010] (3) Place the frozen battery module in a sealed reaction vessel, and introduce organic vapor into the sealed reaction vessel for organic vapor treatment to obtain the battery module after organic vapor treatment.

[0011] (4) Disassemble the battery module after organic vapor treatment, remove the cell fixing adhesive inside the battery module after organic vapor treatment, and obtain the battery cell.

[0012] Furthermore, in step (1), the milled battery module is frozen in a sealed environment at -30℃ to -60℃ for 10h to 24h.

[0013] Furthermore, in step (2), the organic solvent is depressurized to 0.2 to 0.5 atmospheres and then heated to 80°C to 120°C.

[0014] Further, in step (3), the frozen battery module is placed in a sealed reaction vessel and organic vapor is introduced into the sealed reaction vessel for treatment for 1 to 5 hours.

[0015] Furthermore, in step (3), the frozen battery module is placed in a sealed reaction vessel, and the flow rate of the organic vapor introduced into the sealed reaction vessel is 2m. 3 / h~6m 3 / h.

[0016] Furthermore, in step (2), the method of heating the organic solvent by reducing pressure is steam heating.

[0017] Furthermore, the sealed reaction vessel in step (3) is connected to an inlet pipe and an outlet pipe. A flow control valve is installed on the inlet pipe, and organic vapor is introduced into the sealed reaction vessel through the inlet pipe. A shut-off valve is installed on the outlet pipe, and a condensation device is connected to the outlet pipe. The condensation device is connected to a condensate recovery container through a pipe, and a shut-off valve is installed on the pipe connecting the condensation device and the condensate recovery container.

[0018] Furthermore, the condensate in the condensation device is condensate water.

[0019] Further, the process flow for treating organic vapor in step (3) is as follows: open the flow control valve on the inlet pipe and the shut-off valve on the outlet pipe, and the organic vapor is introduced into the sealed reaction tank through the inlet pipe and enters the condensation device through the outlet pipe. After the organic vapor in the condensation device is condensed, it is discharged into the condensate recovery container for recycling. After the organic vapor is introduced into the sealed reaction tank for treatment for 1 to 5 hours, close the flow control valve on the inlet pipe and the shut-off valve on the outlet pipe.

[0020] The beneficial technical effects of the present invention are as follows: In the process of disassembling battery modules, the structural adhesive re-adhesion after warming up makes it difficult to separate the cells and the water film on the surface of the battery cells after freezing causes short circuits. In addition, the structural adhesive between the battery cells becomes brittle and cracks after freezing. The present invention treats the frozen battery module in alcohol organic vapor. The use of organic vapor treatment has the following advantages: (1) Organic vapor condenses into liquid on the surface of the cells to form a uniform organic film, which can isolate water vapor and prevent water vapor from causing short circuit discharge between cells after condensation; (2) Organic vapor can enter the gaps of the modified adhesive more uniformly. The organic vapor with temperature reacts with the polyester adhesive in an alcoholysis reaction, reducing its viscosity and preventing it from re-adhesion after warming up. This ensures the disassembly efficiency of the cells and reduces the disassembly difficulty of the battery module; (3) The organic vapor introduced at a temperature higher than room temperature can warm up the structural adhesive in the module at the same time. The warming process also removes air, further avoiding the short circuit problem caused by water vapor condensation on the surface of the cells. Attached Figure Description

[0021] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0022] See Figure 1 The present invention provides a method for disassembling a battery module, comprising the following steps:

[0023] (1) Mill the positive and negative electrode connecting pieces of the battery module to be disassembled to obtain the milled battery module; freeze the milled battery module to obtain the frozen battery module; freeze the milled battery module in a sealed environment of -30℃ to -60℃ for 10h to 24h.

[0024] (2) The organic solvent is depressurized and heated to obtain organic vapor; the organic solvent is one or more of n-butanol, n-pentanol, phenylethanol, and dimethylhexanol; the organic solvent is depressurized to 0.2 to 0.5 atmospheres and then heated to 80°C to 120°C. The heating method for depressurizing and heating the organic solvent is steam heating.

[0025] (3) Place the frozen battery module in a sealed reaction vessel and introduce organic vapor into the vessel for organic vapor treatment to obtain an organic vapor-treated battery module; place the frozen battery module in a sealed reaction vessel and introduce organic vapor into the vessel for treatment for 1 to 5 hours. The flow rate of the organic vapor introduced into the sealed reaction vessel is 2 m / s. 3 / h~6m 3 The flow rate of organic vapor affects the coverage of the organic film on the surface of the battery module. Too high a flow rate cannot adequately cover the individual battery cells, while too low a flow rate may cause the battery module to overheat. The sealed reaction tank is connected to an inlet pipe and an outlet pipe. A flow control valve is installed on the inlet pipe, through which organic vapor is introduced into the sealed reaction tank. A shut-off valve is installed on the outlet pipe, which is connected to a condensation device. The condensation device is connected to a condensate recovery container via a pipe, and a shut-off valve is installed on the pipe connecting the condensation device and the condensate recovery container. The condensate in the condensation device is condensate water. The process flow for treating organic vapor is as follows: the flow control valve on the inlet pipe and the shut-off valve on the outlet pipe are opened, allowing organic vapor to enter the sealed reaction tank through the inlet pipe and then into the condensation device through the outlet pipe. After condensation, the organic vapor in the condensation device is discharged into the condensate recovery container for recycling. After treating the sealed reaction tank with organic vapor for 1-5 hours, the flow control valve on the inlet pipe and the shut-off valve on the outlet pipe are closed.

[0026] (4) Disassemble the battery module after organic vapor treatment, remove the cell fixing adhesive inside the battery module after organic vapor treatment, and obtain the battery cell.

[0027] The technical solution of the present invention will be further explained and illustrated below through embodiments.

[0028] Example 1

[0029] Obtain the battery module, mill the positive and negative terminal connecting pieces of the battery module to be disassembled to obtain the milled battery module; freeze the milled battery module in a sealed environment at -40℃ for 10 hours to obtain the frozen battery module.

[0030] n-Butanol is heated under reduced pressure to obtain n-butanol organic vapor; the pressure of n-butanol after pressure reduction is 0.5 atmospheres, and the n-butanol is heated to 80°C after pressure reduction. The heating method for n-butanol is steam heating.

[0031] The frozen battery module was placed in a sealed reaction vessel, and n-butanol organic vapor was introduced into the vessel for organic vapor treatment, resulting in a n-butanol-treated battery module. The frozen battery module was then treated with n-butanol organic vapor for 2 hours, yielding the n-butanol-treated battery module; the flow rate of the n-butanol organic vapor introduced into the frozen battery module was 2 m / s. 3 / h. The sealed reaction vessel is connected to an inlet pipe and an outlet pipe. A flow control valve is installed on the inlet pipe, through which n-butanol organic vapor is introduced into the sealed reaction vessel. A shut-off valve is installed on the outlet pipe, which is connected to a condenser. The condenser is connected to a condensate recovery container via a pipe, and a shut-off valve is installed on the pipe connecting the condenser and the condensate recovery container. The condensate in the condenser is condensate water. The process flow for treating n-butanol organic vapor is as follows: the flow control valve on the inlet pipe and the shut-off valve on the outlet pipe are opened, allowing the organic vapor to enter the sealed reaction vessel through the inlet pipe and then enter the condenser through the outlet pipe. The n-butanol organic vapor in the condenser is condensed and discharged into the condensate recovery container for recycling. After treating the sealed reaction vessel with organic vapor for 2 hours, the flow control valve on the inlet pipe and the shut-off valve on the outlet pipe are closed.

[0032] The battery module treated with n-butanol organic vapor was disassembled, and the monomer fixing adhesive inside the battery module was removed to obtain the battery cells.

[0033] Example 2

[0034] Obtain the battery module, mill the positive and negative terminal connecting pieces of the battery module to be disassembled to obtain the milled battery module; freeze the milled battery module in a sealed environment at -40℃ for 24 hours to obtain the frozen battery module.

[0035] n-Butanol is heated under reduced pressure to obtain n-butanol organic vapor; the pressure of n-butanol after pressure reduction is 0.2 atmospheres, and the n-butanol is heated to 100°C after pressure reduction. The heating method for n-butanol is steam heating.

[0036] The frozen battery module was placed in a sealed reaction vessel, and n-butanol organic vapor was introduced into the vessel for organic vapor treatment, resulting in a n-butanol-treated battery module. The frozen battery module was then treated with n-butanol organic vapor for 5 hours, yielding the n-butanol-treated battery module. The flow rate of the n-butanol organic vapor introduced into the frozen battery module was 4 m / s. 3The sealed reaction vessel is connected to an inlet pipe and an outlet pipe. A flow control valve is installed on the inlet pipe, through which n-butanol organic vapor is introduced into the sealed reaction vessel. A shut-off valve is installed on the outlet pipe, which is connected to a condenser. The condenser is connected to a condensate recovery container via a pipe, and a shut-off valve is installed on the pipe connecting the condenser and the condensate recovery container. The condensate in the condenser is condensate water. The process flow for treating n-butanol organic vapor is as follows: the flow control valve on the inlet pipe and the shut-off valve on the outlet pipe are opened, allowing the organic vapor to enter the sealed reaction vessel through the inlet pipe and then through the outlet pipe into the condenser. The n-butanol organic vapor in the condenser is condensed and discharged into the condensate recovery container for recycling. After 5 hours of treatment with organic vapor in the sealed reaction vessel, the flow control valve on the inlet pipe and the shut-off valve on the outlet pipe are closed.

[0037] The battery module treated with n-butanol organic vapor was disassembled, and the monomer fixing adhesive inside the battery module was removed to obtain the battery cells.

[0038] Example 3

[0039] Obtain the battery module, mill the positive and negative terminal connecting pieces of the battery module to be disassembled to obtain the milled battery module; freeze the milled battery module in a sealed environment at -40℃ for 15 hours to obtain the frozen battery module.

[0040] n-Butanol is heated under reduced pressure to obtain n-butanol organic vapor; the pressure of n-butanol after pressure reduction is 0.3 atmospheres, and the n-butanol is heated to 90°C after pressure reduction. The heating method for n-butanol is steam heating.

[0041] The frozen battery module was placed in a sealed reaction vessel, and n-butanol organic vapor was introduced into the vessel for organic vapor treatment, resulting in a n-butanol organic vapor-treated battery module. The frozen battery module was then treated with n-butanol organic vapor for 3 hours, yielding the n-butanol organic vapor-treated battery module. The flow rate of the n-butanol organic vapor introduced into the frozen battery module was 6 m / s. 3The sealed reaction vessel is connected to an inlet pipe and an outlet pipe. A flow control valve is installed on the inlet pipe, through which n-butanol organic vapor is introduced into the sealed reaction vessel. A shut-off valve is installed on the outlet pipe, which is connected to a condenser. The condenser is connected to a condensate recovery container via a pipe, and a shut-off valve is installed on the pipe connecting the condenser and the condensate recovery container. The condensate in the condenser is condensate water. The process flow for treating n-butanol organic vapor is as follows: the flow control valve on the inlet pipe and the shut-off valve on the outlet pipe are opened, allowing the organic vapor to enter the sealed reaction vessel through the inlet pipe and then through the outlet pipe into the condenser. The n-butanol organic vapor in the condenser is condensed and discharged into the condensate recovery container for recycling. After treating the sealed reaction vessel with organic vapor for 3 hours, the flow control valve on the inlet pipe and the shut-off valve on the outlet pipe are closed.

[0042] The battery module treated with n-butanol organic vapor was disassembled, and the monomer fixing adhesive inside the battery module was removed to obtain the battery cells.

Claims

1. A method for disassembling a battery module, characterized in that, The method comprises the following steps: (1) milling the positive and negative electrode connecting pieces of a battery module to be disassembled to obtain a milled battery module; freezing the milled battery module to obtain a frozen battery module; (2) reducing the pressure of an organic solvent and increasing the temperature to obtain organic vapor; the organic solvent is one or more of n-butanol, n-pentanol, phenethyl alcohol, and dimethyl hexanol; (3) placing the frozen battery module in a sealed reaction tank, and introducing the organic vapor into the sealed reaction tank to perform organic vapor treatment, to obtain an organic vapor treated battery module; (4) disassembling the organic vapor treated battery module, and removing the cell fixing glue in the organic vapor treated battery module to obtain battery cells.

2. The method of claim 1, wherein, In step (1), the milled battery module is frozen at -30℃ to -60℃ in a sealed environment for 10h to 24h.

3. The method of claim 1, wherein, In step (2), the organic solvent is reduced to 0.2 to 0.5 atm and then heated to 80℃ to 120℃.

4. The method of claim 1, wherein, In step (3), the frozen battery module is placed in a sealed reaction tank, and the organic vapor is introduced into the sealed reaction tank for 1h to 5h.

5. The method of claim 4, wherein, The frozen battery module in step (3) is placed in a closed reaction tank, and the flow rate of the organic vapor introduced into the closed reaction tank is 2 m 3 / h ~ 6 m 3 / h.

6. The method of claim 3, wherein, In step (2), the heating method for increasing the temperature of the organic solvent is steam heating.

7. The method of claim 4 or 5, wherein In step (3), the sealed reaction tank is connected to a gas inlet pipeline and a gas outlet pipeline, a flow control valve is installed on the gas inlet pipeline, and the organic vapor is introduced into the sealed reaction tank through the gas inlet pipeline; a stop valve is installed on the gas outlet pipeline, the gas outlet pipeline is connected to a condensing device, and the condensing device is connected to a condensed liquid recovery container through a pipeline; a stop valve is installed on the pipeline connecting the condensing device and the condensed liquid recovery container.

8. The method of claim 7, wherein, The condensed liquid in the condensing device is condensed water.

9. The method of claim 7, wherein, In step (3), the process of organic vapor treatment is as follows: the flow control valve on the gas inlet pipeline and the stop valve on the gas outlet pipeline are opened, the organic vapor is introduced into the sealed reaction tank through the gas inlet pipeline and enters the condensing device through the gas outlet pipeline, the organic vapor in the condensing device is condensed and discharged into the condensed liquid recovery container for recycling; after the organic vapor is introduced into the sealed reaction tank for 1h to 5h, the flow control valve on the gas inlet pipeline and the stop valve on the gas outlet pipeline are closed.

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