CN-122025898-A - Method for separating and recovering active material of positive electrode of retired lithium ion battery

Abstract

The invention discloses a method for separating and recycling active materials of a retired lithium ion battery anode, which belongs to the technical field of battery recycling and aims at the problems of high calcination temperature, high energy consumption, low active material recovery rate, easy corrosion of aluminum foil, secondary pollution and the like in the prior art. The method has the advantages of low calcination temperature, low energy consumption, simple process, green and no waste liquid pollution, nearly 100 percent of recovery rate of active substances, no residue and no corrosion of the separated aluminum foil, direct recycling, suitability for large-scale green recovery of the anode plate of the retired lithium ion battery, and good economic and environmental benefits.

Inventors

• HE JIABAO
• LIU ZIHAN
• PENG YAHUI
• ZHANG JIAFU
• LEI LEI
• WANG LI
• YANG ZHIGUO

Assignees

• 六安职业技术学院

Dates

Publication Date

20260512

Application Date

20260403

Claims (8)

1. 1. A method for separating and recovering a positive electrode active material of a retired lithium ion battery, comprising the following steps: s1, taking a retired lithium ion battery positive plate containing a small amount of residual electrolyte, and placing the retired lithium ion battery positive plate in calcining equipment protected by inert atmosphere for calcining treatment; S2, transferring the calcined positive electrode plate into deionized water, soaking at a constant temperature until active substances and the aluminum foil current collector are automatically stripped; s3, collecting the stripped active substances and the complete aluminum foil, and completing separation and recovery.
2. 2. The method for separating and recovering active materials of a positive electrode of a retired lithium ion battery according to claim 1, wherein the active material component of the positive electrode plate is lithium iron phosphate, the binder is polyvinylidene fluoride (PVDF), and the current collector is aluminum foil.
3. 3. The method for separating and recovering positive electrode active materials of retired lithium ion battery according to claim 2, wherein the calcining atmosphere is one or two mixed inert gases of nitrogen and argon.
4. 4. The method for separating and recovering the active material of the positive electrode of the retired lithium ion battery according to any one of claims 1-3, wherein the calcination temperature is 300-550 ℃ and the calcination time is 5 min-6 h.
5. 5. The method for separating and recovering active materials of a positive electrode of a retired lithium ion battery according to claim 4, wherein the soaking temperature is 50-100 ℃ and the soaking time is 0.5-24 h.
6. 6. The method of claim 5, wherein the soaking temperature is inversely related to the soaking time, and the higher the temperature, the shorter the soaking time is required.
7. 7. The method for separating and recovering positive electrode active material of retired lithium ion battery according to claim 6, wherein the calcination temperature is 300 ℃, the calcination time is 30min, the soaking temperature is 50 ℃, and the soaking time is 12h.
8. 8. The method for separating and recovering positive electrode active material of retired lithium ion battery according to claim 6, wherein the calcination temperature is 380 ℃, the calcination time is 30min, the soaking temperature is 100 ℃, and the soaking time is 0.5h.

Description

Method for separating and recovering active material of positive electrode of retired lithium ion battery Technical Field The invention relates to an environment-friendly technology, in particular to a method for separating and recycling active materials of a positive electrode of a retired lithium ion battery. Background Industry predicts that the worldwide retired lithium battery of 2030 will have over 2000 kilotons, which contains significant amounts of high-value metals (e.g., lithium, cobalt, nickel) and carbon materials. The positive and negative plates are used as core components of the battery (accounting for more than 30% of the mass of the battery), and the efficient recovery of the positive and negative plates is the key of recycling resources. The recovery method of the electrode material of the retired lithium ion battery comprises two steps of extracting high-value metal, converting the high-value metal into metal, metal alloy or metal salt through hydrometallurgy or pyrometallurgical technology, and recovering the electrochemical performance of the electrode material through repairing the crystal structure of the electrode material by a physicochemical method. However, both of the above recovery methods face the difficult problem of separation between the active material and the current collector. The recovered positive pole piece of the lithium ion battery comprises an active component, a conductive agent, a binder, an aluminum foil current collector, residual electrolyte and the like, wherein the binder enables active substances to be in close contact with the current collector, the aluminum foil current collector is thin and flexible, the traditional physical method is difficult to realize high-efficiency separation of the active substances and the current collector, the recovery rate of the active substances is low, and the content of aluminum in the black powder is high. The patent document with publication number CN121565978A discloses a method for separating and recycling anode and cathode materials of waste lithium iron phosphate injection battery cores, wherein active substances can be separated from an aluminum current collector through vibration screening after calcination for a certain time (1.5-3 h) at a high temperature (400-650 ℃) under the protection of inert gases (including nitrogen, argon or helium), and the recycling rate of the anode materials is up to 99.32%. The patent document with publication number CN105489960A discloses a separation method of a current collector and an active material of a lithium battery, wherein a recovered electrode plate is soaked in deionized water at 75-85 ℃, an anionic surfactant and hydrochloric acid are added, the current collector and the active material can be separated after heat preservation and stirring for 4-6 hours, and the recovery rate of the positive electrode material is 89.9% at the highest. However, the problems of high energy consumption, low recovery rate of the cathode material and the like in the prior art are solved, and the problem of difficult separation between the active material and the current collector is not thoroughly solved. Disclosure of Invention Aiming at the problems of high calcining temperature, high energy consumption, low recovery rate of active substances, easy corrosion and damage of aluminum foil, pollution of waste liquid and the like in the existing separation technology of the anode active materials of the retired lithium ion battery, the invention provides the method for separating and recovering the anode active materials of the retired lithium ion battery, which realizes low-temperature low-consumption high-efficiency green separation, ensures nearly 100 percent recovery of active substances, and simultaneously protects the aluminum foil from complete residue and corrosion. In order to achieve the technical purpose, the technical scheme adopted by the invention is as follows. A method for separating and recycling active materials of a positive electrode of a retired lithium ion battery comprises the following steps: taking a retired lithium ion battery positive plate containing a small amount of residual electrolyte, and placing the retired lithium ion battery positive plate in calcining equipment protected by inert atmosphere for calcining treatment; Transferring the calcined positive electrode plate into deionized water, soaking at constant temperature until the active substance and the aluminum foil current collector are automatically stripped; and collecting the stripped active substances and the complete aluminum foil, and completing separation and recovery. The active material component of the positive electrode plate is lithium iron phosphate, the binder is polyvinylidene fluoride (PVDF), and the current collector is aluminum foil. The calcining atmosphere is one or two mixed inert gases of nitrogen and argon. The calcination temperature is 300-550 ℃, preferably 300 ℃, and the calcination