CN-121983695-A - Stripping and recycling method for lithium battery positive plate

CN121983695ACN 121983695 ACN121983695 ACN 121983695ACN-121983695-A

Abstract

The invention discloses a stripping and recycling method for a lithium battery positive plate, and belongs to the technical field of battery recycling. The recycling method comprises the steps of shearing waste ternary positive plates to obtain first positive plate fragments, immersing the first positive plate fragments into a solution containing a monomer and an initiator to enable the solution to completely permeate the first positive plate fragments to obtain second positive plate fragments, carrying out in-situ polymerization, and then carrying out mechanical crushing and sorting to obtain positive black powder and positive current collector respectively, wherein the waste ternary positive plates comprise positive current collectors and positive material layers arranged on at least one surface of the positive current collectors. According to the invention, the separation of the positive electrode active material layer and the positive electrode current collector is realized by combining interface in-situ embrittlement and mechanical crushing, so that the problem that the recovery of the positive electrode material cannot simultaneously meet the requirements of high yield, high purity and low damage is solved.

Inventors

LIU KELU
WANG TAO
YANG LEI
LI LIMIN
Yan Ruguo
Hua Runjie

Assignees

江西天奇金泰阁钴业有限公司

Dates

Publication Date: 20260505
Application Date: 20260129

Claims (10)

1. The stripping recovery method of the lithium battery positive plate is characterized by comprising the following steps: s1, shearing waste ternary positive plates to obtain first positive plate fragments; s2, stirring an initiator and a monomer to obtain a solution containing the monomer; S3, immersing the first positive plate fragments in the step S1 into the solution containing the monomers in the step S2, so that the solution containing the monomers completely permeates the first positive plate fragments to obtain second positive plate fragments; s4, taking out the second positive plate fragments, and carrying out in-situ polymerization to obtain third positive plate fragments containing in-situ polymerization products; s5, mechanically crushing and sorting the third positive plate fragments to obtain positive black powder and a positive current collector respectively; in S1, the waste ternary positive plate comprises a positive current collector and a positive material layer arranged on at least one surface of the positive current collector.
2. The stripping recovery method according to claim 1, characterized in that in S1, the positive electrode current collector is aluminum foil; And the sheet diameter of the first positive plate fragments is 0.5-2 cm.
3. The stripping recovery method according to claim 1, characterized in that in S2, the mass ratio of the initiator to the monomer is 0.2-1.0:100; the monomer comprises at least one of methyl methacrylate and styrene; The initiator comprises at least one of azo initiator and peroxide initiator; preferably, the initiator comprises at least one of benzoyl peroxide and azobisisobutyronitrile; the monomer-containing solution further comprises an organic solvent, wherein in a solution system containing the organic solvent, the mass fraction of the monomer is 50-80%, and the mass ratio of the initiator to the monomer is 0.2-1.0:100; the organic solvent comprises at least one of N-methyl pyrrolidone and dimethylformamide.
4. The stripping recovery method according to claim 1, wherein in S3, the step of completely penetrating the monomer-containing solution into the first positive electrode sheet fragments is to completely penetrate the monomer-containing solution into the inside of the positive electrode material layer of the first positive electrode sheet fragments and the bonding interface between the positive electrode material layer and the positive electrode current collector.
5. The stripping recovery method as recited in claim 1 or 4, wherein in S3, the permeation is achieved by pressure permeation after immersing the first positive electrode sheet chips in a monomer-containing solution; the pressure of the pressure permeation is 0.02-0.05 MPa, and the time is 0.5-4 h.
6. The stripping recovery method as recited in claim 1, wherein in S4, the in-situ polymerization is thermal polymerization of the second positive electrode sheet pieces.
7. The method according to claim 6, wherein the thermal polymerization is performed at a temperature of 60 to 70 ℃ for a time of 4 to 6 hours.
8. The method according to claim 1, wherein in S5, the mechanical pulverization speed is 1200 to 1800r/min.
9. The peel recovery method of claim 1, wherein in S5, the sorting comprises at least one of screen sieving and air flow sorting.
10. A positive electrode material obtained by the stripping recovery method according to any one of claims 1 to 9.

Description

Stripping and recycling method for lithium battery positive plate Technical Field The invention relates to the technical field of lithium ion battery recovery, in particular to a stripping recovery method for a lithium battery positive plate. Background The waste lithium battery pole pieces contain non-renewable resources such as nickel, cobalt, manganese, lithium, aluminum and the like, and the key first step is to effectively strip the pole powder in the pole pieces from the current collector in order to realize the recycling of the resources. At present, aiming at the positive plate of the waste lithium battery, the main stripping technical means are a direct mechanical crushing method, a heat treatment and mechanical crushing combined method, a solvent method and the like. The direct mechanical crushing method has the following problems that the positive plate separates the positive powder from the current collector through physical means such as mechanical impact, collision, vibration, friction and the like, and then the positive powder is obtained through separation according to gravity. The recovery mode cannot meet the requirements of high purity and high yield, the larger the mechanical crushing force is, the higher the yield is, but the higher the aluminum impurity introduction amount is, and the smaller the mechanical crushing force is, the higher the purity of the polar powder is, but the yield is reduced. The high-temperature pyrolysis combined mechanical crushing method is to remove the binder through high-temperature incineration, then mechanically crush and sort, and strip and recycle the polar powder. The recovery rate of the method is highest (> 98%), and the method is a recovery method commonly used at present. However, the anode material is greatly deactivated after heat treatment, the aluminum foil is also oxidized and embrittled, more aluminum scraps generated during crushing are introduced into the anode powder, the introduction amount of aluminum is generally 2-5%, and the purity of the anode powder is reduced, so that the anode powder is not beneficial to subsequent wet or physical regeneration. The solvent method is that the positive plate is generally prepared by dissolving the binder (PVDF) by using solvents such as N-methyl pyrrolidone, etc., but the solvent has high cost and high toxicity, has limited effect on the binder in the depth of the pores, is difficult to realize large-scale production, and does not realize large-scale application at present. Based on the problems of the stripping method, a pole piece stripping technology which is efficient, low in cost, environment-friendly, high in purity and free from damaging the regeneration of subsequent materials is urgently needed at present. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a stripping and recycling method for a lithium battery positive plate. According to the invention, the separation of the positive electrode active material layer and the positive electrode current collector is realized by combining interface in-situ embrittlement with mechanical crushing, and a hard and brittle new polymer is formed in the positive electrode material layer and at the junction of the positive electrode active material layer and the current collector by in-situ polymerization, so that the bonding interface is 'distracted' and embrittled from the inside, the mechanical energy required by stripping is greatly reduced, the recovery rate of the positive electrode material is effectively improved, the aluminum content in the positive electrode material is reduced, and the problem that the recovery of the positive electrode material cannot simultaneously meet the requirements of high yield, high purity and low damage is solved. The technical scheme of the invention is as follows: The invention provides a stripping recovery method of a lithium battery positive plate, which comprises the following steps: s1, shearing waste ternary positive plates to obtain first positive plate fragments; s2, stirring an initiator and a monomer to obtain a solution containing the monomer; S3, immersing the first positive plate fragments in the step S1 into the solution containing the monomers in the step S2, so that the solution containing the monomers completely permeates the first positive plate fragments to obtain second positive plate fragments; s4, taking out the second positive plate fragments, and carrying out in-situ polymerization to obtain third positive plate fragments containing in-situ polymerization products; s5, mechanically crushing and sorting the third positive plate fragments to obtain positive black powder and a positive current collector respectively; in S1, the waste ternary positive plate comprises a positive current collector and a positive material layer arranged on at least one surface of the positive current collector. Preferably, in S1, the positive current collector is an aluminum foil;