CN-122000517-A - Efficient regeneration method of waste lithium iron phosphate battery anode material

Abstract

The invention belongs to the technical field of lithium iron phosphate batteries, and particularly relates to a high-efficiency regeneration method of a waste lithium iron phosphate battery positive electrode material, which comprises the following steps of S1, pretreating the waste material, namely removing an aluminum foil current collector of a retired power battery positive electrode plate, collecting lithium iron phosphate powder, performing ball milling and drying treatment to obtain waste LFP powder, S2, preparing a lithium supplementing solution, namely preparing caffeic acid and LiOH H 2 O is mixed to prepare a liquid-phase lithium supplementing solution, S3, the liquid-phase lithium supplementing restoration is carried out, namely SLFP is added into the lithium supplementing solution, stirring reaction is carried out at a preset temperature, LFP powder for lithium supplementing restoration is obtained after washing and drying, S4, heat treatment and carbon coating are carried out, namely LLFP is mixed with glucose, heating heat treatment is carried out under inert protective atmosphere, and the regenerated lithium iron phosphate powder is obtained after natural cooling. Provides a solution with both performance advantages and economy for recycling the waste lithium iron phosphate batteries.

Inventors

• HAN JIAXING
• ZHUANG YAN
• ZHU BINGLONG
• ZHEN AIGANG
• ZHANG WEI
• ZHANG MINGDAO
• JIA HAILANG
• WU JING

Assignees

• 江苏理工学院

Dates

Publication Date

20260508

Application Date

20260203

Claims (8)

1. 1. The efficient regeneration method of the waste lithium iron phosphate battery anode material is characterized by comprising the following steps of: s1, pretreating a waste material, namely removing an aluminum foil current collector of a positive plate of the retired power battery, collecting lithium iron phosphate powder, and performing ball milling and drying treatment to obtain waste LFP powder; S2, preparing a lithium supplementing solution, namely preparing caffeic acid Mixing according to the molar ratio of 1:0.9-1.1 to prepare and form a liquid phase lithium supplementing solution; s3, liquid-phase lithium supplementing and repairing, namely adding the SLFP into the lithium supplementing solution in the step S2, stirring and reacting at a preset temperature, and washing and drying to obtain LFP powder for lithium supplementing and repairing; S4, heat treatment and carbon coating, namely mixing LLFP with glucose according to the mass ratio of 10:0.8-1.2, heating up and heat treatment under inert protective atmosphere, and naturally cooling to obtain the regenerated lithium iron phosphate powder.
2. 2. The efficient regeneration method of the waste lithium iron phosphate battery positive electrode material according to claim 1, wherein in the step S1, the ball-milling ball material ratio is 10:1, the ball-milling rotating speed is 300r/min, and the ball-milling time is 2 hours.
3. 3. The efficient regeneration method of the waste lithium iron phosphate battery positive electrode material according to claim 1, wherein in the step S1, drying is vacuum drying, the drying temperature is 60 ℃, and the drying time is 12 hours.
4. 4. The efficient regeneration method of the waste lithium iron phosphate battery positive electrode material according to claim 1, wherein in the step S2, the concentration of the liquid phase lithium supplementing solution is 0.05-0.2 mol/L.
5. 5. The efficient regeneration method of the waste lithium iron phosphate battery positive electrode material according to claim 1, wherein in the step S3, the preset temperature is 60 ℃, and the stirring reaction time is 6 hours.
6. 6. The method for efficiently regenerating the waste lithium iron phosphate battery positive electrode material according to claim 1, wherein in the step S4, the inert protective atmosphere is a mixed atmosphere of Ar and H 2 .
7. 7. The method for efficiently regenerating the waste lithium iron phosphate battery positive electrode material according to claim 6, wherein the volume ratio of Ar to H 2 in the mixed atmosphere of Ar and H 2 is 95:5.
8. 8. The efficient regeneration method of the waste lithium iron phosphate battery positive electrode material according to claim 1, wherein in the step S4, the temperature rising rate is 5 ℃ per minute, the heat treatment temperature is 700 ℃, and the heat preservation time is 2 hours.

Description

Efficient regeneration method of waste lithium iron phosphate battery anode material Technical Field The invention belongs to the technical field of lithium iron phosphate batteries, and particularly relates to a high-efficiency regeneration method of a waste lithium iron phosphate battery anode material. Background With the wide application of lithium ion batteries, the recovery and reuse of waste batteries become a problem to be solved urgently. Lithium iron phosphate (LiFePO 4) batteries are widely used in electric vehicles and energy storage devices due to their high stability and safety. However, after long-term use, lithium iron phosphate batteries may suffer from significant degradation in battery performance due to lithium loss and conversion of iron phosphate. Existing regeneration methods rely mostly on high temperature reduction or direct high temperature recovery, but these methods generally require removal of impurities from the battery, and are complex and costly. In the prior art, patent CN202010825386.5 provides a method for repairing and regenerating a waste lithium iron phosphate battery anode material, which comprises the steps of obtaining retired lithium iron phosphate powder through fine disassembly, and carrying out treatment at 700-900℃,Calcining under the condition of oxygen partial pressure to remove carbon, adding a lithium source (lithium carbonate and the like) and a carbon source (sucrose or glucose) for ball milling and mixing, and finally calcining under the inert atmosphere of 650-800 ℃ to realize regeneration, but the method needs multi-step high-temperature treatment, has high energy consumption and complex flow, and does not consider the side reaction problems of iron dissolution and the like. Patent CN202110939900.2 discloses a method for regenerating the positive electrode waste of a scrapped lithium iron phosphate battery, which adopts a multi-component lithium supplementing modifier containing lithium carbonate, starch, silver nitrate, titanium sulfate and carbon nano tubes, and combines a 300-400W microwave hydrothermal reaction at 175-215 ℃ and a 600-800 ℃ calcination process, but the preparation steps of the lithium supplementing modifier are complicated, the microwave hydrothermal process needs special high-temperature high-pressure equipment, the cost is high, and the diffusion efficiency of lithium ions cannot be synchronously improved. Patent CN202310867048.1 proposes that regeneration is realized through carboxymethyl cellulose lithium, waste lithium iron phosphate powder is separated by acetonitrile washing and 500 ℃ calcination for 3 hours pretreatment, lithium deficiency is tested by ICP-OES, then the waste lithium iron phosphate powder is mixed with carboxymethyl cellulose lithium, and calcination is carried out for 10-15 hours under 600-700 DEG CAr/H 2 atmosphere, but the lithium deficiency is required to be detected in advance, the flow is complicated, the high-temperature calcination time is long, the energy consumption is large, and a side reaction inhibition mechanism is lacked. Therefore, developing a high-efficiency and low-cost lithium iron phosphate regeneration method becomes a technical problem in the current battery recovery field. Disclosure of Invention The invention aims to provide a high-efficiency regeneration method of a waste lithium iron phosphate battery anode material so as to solve the problems. In order to achieve the above object, the present invention provides the following solutions: a high-efficiency regeneration method of a waste lithium iron phosphate battery anode material comprises the following steps: s1, pretreating a waste material, namely removing an aluminum foil current collector of a positive plate of the retired power battery, collecting lithium iron phosphate powder, and performing ball milling and drying treatment to obtain waste LFP powder; S2, preparing a lithium supplementing solution, namely preparing caffeic acid Mixing according to the molar ratio of 1:0.9-1.1 to prepare and form a liquid phase lithium supplementing solution; s3, liquid-phase lithium supplementing and repairing, namely adding the SLFP into the lithium supplementing solution in the step S2, stirring and reacting at a preset temperature, and washing and drying to obtain LFP powder for lithium supplementing and repairing; S4, heat treatment and carbon coating, namely mixing LLFP with glucose according to the mass ratio of 10:0.8-1.2, heating up and heat treatment under inert protective atmosphere, and naturally cooling to obtain the regenerated lithium iron phosphate powder. Preferably, in the step S1, the ball-milling ball-material ratio is 10:1, the ball-milling rotating speed is 300r/min, and the ball-milling time is 2 hours. Preferably, in step S1, the drying is vacuum drying, the drying temperature is 60 ℃, and the drying time is 12 hours. Preferably, in the step S2, the concentration of the liquid-phase lithium supplementing solution is 0.