Disassembling method for taking out battery cell from retired power battery pack

Abstract

The invention belongs to the technical field of battery recovery, and particularly relates to a disassembling method for taking out a battery cell from a decommissioned power battery pack, which comprises the following steps of: 1, selecting an ethyl acetate solvent, 2, uniformly punching a sealing plate of the battery pack, establishing a solvent immersion channel through which the ethyl acetate solvent can pass, and taking out the battery cell from the decommissioned power battery pack. 3, injecting an ethyl acetate solvent into the solvent immersion channel, and sealing and infiltrating to swell the structural adhesive in the battery pack, 4, uncovering the sealing plate, and removing the swelled structural adhesive, and 5, taking out the battery cell. According to the invention, the battery cell can be efficiently and safely taken out from the retired power battery pack, and meanwhile, the damage to the battery cell is reduced as much as possible, so that the echelon utilization of the battery cell is realized, the recycling rate of resources is improved, the environmental pollution is reduced, and the requirement of sustainable development is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery recycling, and in particular relates to a disassembly method for removing battery cells from a retired power battery pack. Background Art

[0002] As the global energy crisis and environmental pollution become increasingly serious, the development of new energy technology has received widespread attention. As an important application field of new energy technology, new energy vehicles are developing rapidly. As the core component of new energy vehicles, the performance of power batteries directly affects the endurance and safety of new energy vehicles. However, with the popularization of new energy vehicles, a large number of power batteries are retired after reaching the end of their service life. How to effectively recycle and reuse these retired power batteries has become an important issue in the development of new energy technology.

[0003] At present, the recycling technology of power batteries mainly includes direct recycling and cascade utilization. Direct recycling mainly refers to the extraction of valuable metals such as lithium, cobalt, nickel, etc. from retired power batteries and then using them to produce new batteries or other products. Cascade utilization refers to the continued use of retired power batteries in situations where their performance has declined but they can still meet certain low-power requirements, such as energy storage systems, low-speed electric vehicles, etc.

[0004] However, there are many problems with the existing power battery disassembly and recycling technology. Although the mechanical disassembly method can retain the battery cells relatively intact, it has high disassembly intensity, low efficiency, and is easy to damage the battery cells, affecting their cascade utilization value. Although the chemical treatment disassembly method can separate the battery components more thoroughly, the chemical substances in the treatment process may cause secondary pollution to the environment, and the treatment cost is high. Although the crushing disassembly method has a fast disassembly speed, it will cause serious damage to the battery cells, making it almost impossible to achieve cascade utilization.

[0005] In view of this, a new power battery disassembly method is urgently needed to solve the above-mentioned problems. Summary of the invention

[0006] The purpose of the present invention is to provide a disassembly method for removing battery cells from retired power battery packs, which can efficiently and safely remove battery cells from retired power battery packs while minimizing damage to the battery cells, so as to achieve cascade utilization of battery cells, improve resource recycling rate, reduce environmental pollution, and meet the requirements of sustainable development.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A disassembly method for removing a battery cell from a retired power battery pack comprises the following steps:

[0009] The first step: select ethyl acetate solvent;

[0010] Step 2: Evenly punch holes on the sealing plate of the battery pack to establish a solvent immersion channel that allows the ethyl acetate solvent to pass through;

[0011] Step 3: inject ethyl acetate solvent into the solvent immersion channel and seal it to swell the structural glue in the battery pack;

[0012] Step 4: Open the cover and remove the swollen structural adhesive;

[0013] Step 5: Remove the battery.

[0014] The technical effects achieved by the present invention are:

[0015] The ethyl acetate solvent of the present invention has strong swelling properties for various structural adhesives on the battery pack, and the adhesion of the adhesive can be eliminated after soaking for several hours. The invention is non-conductive, has low sol heat, does not damage the battery cell, does not swell insulating tape, PE film, etc., and does not dissolve the outer insulating layer of daily electric wires. The invention is a safe and reliable sol solvent. The battery cell can be sucked or grabbed by mechanical force and taken out by the sol soaking method or the sol immersion method, so as to realize industrial production. According to this method, an automatic assembly line can be designed to realize large-scale production, and the battery cell can be efficiently and safely taken out from the retired power battery pack, while minimizing the damage to the battery cell, so as to realize the cascade utilization of the battery cell, improve the recycling rate of resources, reduce environmental pollution, and meet the requirements of sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the results of the outer insulation layer of the wire being infiltrated by different solvents during the test process of the present invention. DETAILED DESCRIPTION

[0017] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific embodiments of the present invention, and does not strictly limit the scope of protection of the specific claims of the present invention.

[0018] A disassembly method for removing a battery cell from a retired power battery pack comprises the following steps:

[0019] S1: selecting ethyl acetate solvent (including ethyl acetate of different concentrations);

[0020] See also Figure 1 Through repeated testing and screening, multiple solvent comparison tests, from laboratory tests to factory technical application tests, step-by-step verification and evaluation (compared with NMP solvent: for the same infiltration or immersion, NMP generates a lot of heat and is very easy to dissolve the outer insulation layer of daily-use wires, such as Figure 1, there are potential safety hazards), it is confirmed that ethyl acetate solvent has strong swelling properties for various structural adhesives on the battery pack, eliminates the adhesion of the adhesive, is non-conductive, has low sol heat, does not damage the battery cell, does not swell insulating tapes, PET films, etc., does not dissolve the outer insulation layer of daily-use wires, and only swells slightly;

[0021] S2: drilling holes evenly on the sealing plate of the battery pack to establish a solvent immersion channel through which the ethyl acetate solvent can pass;

[0022] When drilling holes, place the battery pack horizontally. First, remove all screws (including the screws on the wiring port sealing plate), and evenly drill several holes on the sealing metal plate with a depth not exceeding 2.5mm, generally 2.3mm is appropriate (the specific drilling depth should be less than the total thickness of the sealing plate and the adhesive layer by 0.2mm), to avoid damaging the internal battery cells when drilling. A larger hole diameter is better, so that the solvent can flow quickly into the battery pack. The propulsion force is small and even when drilling, and the entire surface is cleaned and used as a solvent channel;

[0023] S3: injecting ethyl acetate solvent into the solvent immersion channel and sealing and infiltrating it to swell the structural glue in the battery pack;

[0024] Use a syringe or other tool to quickly fill each hole with ethyl acetate solvent, cover the metal sealing plate with multiple layers (6 to 10 layers, or determined by experiment during the experiment) of pure cotton gauze, and then pour ethyl acetate solvent in the center of the gauze until it is wet all around, and then cover the gauze with a layer of PE film about 0.06mm thick, and seal it with tape. Let it stand at room temperature for about 6 hours, so that the structural adhesive will swell better. All structural adhesives that have been soaked in the solvent for about 5 hours will swell and lose their adhesion;

[0025] S4: Open the sealing plate and remove the swollen structural adhesive;

[0026] Roll up the multi-layer gauze and PE film at the same time, put them into a bag and seal them for later use. Use a spatula to remove the surrounding glue in time, use a flat-bladed screwdriver and a flat-bladed crowbar or other tools to open the wiring port sealing plate, and then use the same method to open a hole from the outside of the wiring port, put on the traction rope, use a crane or other device to slowly open the sealing plate;

[0027] S5: Remove the battery cell.

[0028] Use a suction cup or non-conductive gripper to remove the battery cell. If it is difficult to grab, re-swell the structural glue in the battery pack. Depending on the degree of difficulty, the re-swelling methods include:

[0029] a. Wetting the sol again;

[0030] If it is just a matter of normal difficulty to grab the battery cell, the battery pack is returned to step S3, and after soaking the battery module for a certain period of time, the battery cell is grabbed.

[0031] b. Soak in sol.

[0032] If it is particularly difficult to grab the battery cell, remove the battery module (the battery module is a structure that combines multiple battery cells into one), all surrounding wiring devices and wires, and put the battery pack into an appropriate (just easy to fit) sealed container deep underground, surrounded by guardrails and equipped with fire-fighting facilities. It is safest to soak it with an appropriate amount of ethyl acetate solvent (just enough to cover the battery pack) for about 5 hours. After the soaking is completed, take out the battery pack and grab the battery cell in time. Multiple battery packs can be soaked at the same time; the ethyl acetate solvent used for soaking can be reused;

[0033] By using the immersion method, steps S2, S3 and S4 can be bypassed. Before immersion, all wiring devices and wires around the battery module can be removed by various means.

[0034] Since ethyl acetate solvent has strong swelling properties for various structural adhesives on battery packs, the adhesion of the adhesive can be eliminated after a few hours of immersion. It is non-conductive, has low sol heat, does not damage the battery cells, does not swell insulating tapes, PE films, etc., and does not dissolve the outer insulation layer of daily wires. It is a safe and reliable sol solvent. Through the sol infiltration method or the sol immersion method, with the help of mechanical force, the battery cells can be sucked or grabbed and taken out to achieve industrial production. According to this method, it can be designed into an automatic assembly line to achieve large-scale production.

[0035] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to the conventional means in the art unless otherwise specified and limited.

Claims

1. A disassembly method for removing cells from a retired power battery pack, characterized in that: The following steps are involved: S1: ethyl acetate solvent is selected; S2: drilling holes evenly on the sealing plate of the battery pack to establish a solvent immersion channel through which the ethyl acetate solvent can pass; S3: injecting ethyl acetate solvent into the solvent immersion channel and sealing and infiltrating it to swell the structural glue in the battery pack; S4: Open the sealing plate and remove the swollen structural adhesive; S5: Remove the battery cell.

2. The disassembly method according to claim 1, characterized in that: When drilling holes in step S2, the battery pack is first placed horizontally and all screws are removed, and then holes are evenly drilled on the sealing plate to serve as solvent immersion channels.

3. The disassembly method according to claim 2, characterized in that: The depth of the punching in step S2 does not exceed 2.5 mm.

4. The disassembly method according to claim 1, characterized in that: In step S3, each well is quickly filled with ethyl acetate solvent, and the sealing plate is covered with multiple layers of pure cotton gauze, and then the ethyl acetate solvent is poured on the gauze until it is moistened all around, and then the gauze is covered with a PE film for sealing.

5. The disassembly method according to claim 4, characterized in that: The sealing time in step S3 is 6 hours.

6. The disassembly method according to claim 1, characterized in that: In step S5, a suction cup or a non-conductive gripper is used to remove the battery cell. If it is difficult to grab, the structural glue in the battery pack is swollen again. The method of swollen again includes: a. Wetting the sol again; b. Soak in sol.

7. The disassembly method according to claim 6, characterized in that: The method a is to return the battery pack to step S3, soak the battery module for a certain period of time, and then grab the battery cell.

8. The disassembly method according to claim 6, characterized in that: In the method b, all the wiring devices and wires around the battery module are removed, and the battery pack is placed in a sealed container, which is then placed underground and the battery pack is soaked in ethyl acetate solvent. After the soaking is complete, the battery pack is taken out and the battery cells are grabbed.

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