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CN-122025890-A - Environment-friendly regeneration method for waste lithium battery anode material coated with bio-based carbon

CN122025890ACN 122025890 ACN122025890 ACN 122025890ACN-122025890-A

Abstract

The application relates to the field, in particular to a green regeneration method of a waste lithium battery anode material coated by bio-based carbon. The preparation method comprises the following steps of S1, raw material pretreatment, S2, foreign matter removal, S3, coating carbonization, mixing the impurity removal material with a bio-based carbon source coating material, dispersing grinding, spray drying, carbonization repairing and carbonization material, S4, modification doping, surface modification, boron source doping, crushing and packaging of the carbonized material in sequence, and obtaining the bio-based carbon coated regenerated anode material, wherein the bio-based carbon source coating material is used for regenerating the waste lithium battery anode material, so that the regenerated lithium battery anode material has better reversible capacity, circulation capacity retention rate, tap density and first coulomb efficiency, and has environmental protection.

Inventors

  • XIA ZHENYU
  • FENG PING

Assignees

  • 东莞市三墨材料有限公司

Dates

Publication Date
20260512
Application Date
20260209

Claims (10)

  1. 1. The green regeneration method of the bio-based carbon-coated waste lithium battery anode material is characterized by comprising the following steps of: s1, raw material pretreatment, namely disassembling and classifying the waste lithium battery anode material to obtain a battery anode material; s2, removing foreign matters, namely removing impurities from the battery cathode material to obtain an impurity-removed material; s3, coating and carbonizing, namely mixing the impurity removing material with the bio-based carbon source coating material, and performing dispersion grinding, spray drying and carbonization repairing to obtain a carbonized material; s4, modifying and doping, namely sequentially carrying out surface modification, boron source doping, crushing and packaging on the carbonized material to obtain a boron doped bio-based carbon coated regenerated anode material; The bio-based carbon source coating material comprises a bio-based hydroxyl polymer water pre-dispersion liquid, natural rubber latex, a water-soluble rosin resin liquid, a poly (3, 4-ethylenedioxythiophene) -poly (styrenesulfonic acid) water dispersion liquid and an emulsifier in a weight ratio of 10 (30-40) (15-23) (1-2) (0.5-2).
  2. 2. The green regeneration method of the bio-based carbon coated waste lithium battery anode material of claim 1, wherein the bio-based hydroxyl polymer of the bio-based hydroxyl polymer water pre-dispersion is one or a combination of a plurality of hydroxyl chitosan, sodium hydroxymethyl cellulose and polyhydroxyalkanoate.
  3. 3. The green regeneration method of the bio-based carbon-coated waste lithium battery anode material of claim 2, wherein the bio-based hydroxyl polymer comprises hydroxyl chitosan, sodium hydroxymethyl cellulose and polyhydroxyalkanoate.
  4. 4. The green recycling method of the bio-based carbon-coated waste lithium battery anode material of claim 3, wherein the polyhydroxyalkanoate is one or more of poly 3-hydroxybutyrate, polyhydroxyvalerate and poly 3-hydroxybutyrate-3-hydroxyvalerate copolymer.
  5. 5. The green regeneration method of the bio-based carbon-coated waste lithium battery anode material according to any one of claims 1 to 4, wherein the bio-based carbon source coating material is obtained by the following method: 1) Slowly dripping water-soluble rosin resin liquid and 1/2 emulsifier at a dripping rate of 1-5mL/min, and continuously stirring for 10-20min after dripping to fully compatibilize the latex and the rosin resin to obtain emulsion A; 2) Slowly pouring the water pre-dispersion liquid of the bio-based hydroxyl polymer into the emulsion A, increasing the stirring speed to 600-700r/min, and stirring for 20-30min; 3) Stirring is kept, aqueous dispersion of poly (3, 4-ethylenedioxythiophene) -poly (styrenesulfonic acid) is slowly dripped, stirring is carried out for 20-30min after dripping is completed, the conductive phase is uniformly dispersed in the composite emulsion, homogenizing is carried out, the PH is regulated to 7.5-8.5, and curing is carried out, thus obtaining the bio-based carbon source coating material.
  6. 6. The green regeneration method of the bio-based carbon coated waste lithium battery anode material according to claim 1, wherein the impurity removal process in the step S2 is specifically as follows: Screening by a multi-layer vibrating screen, separating impurities with different particle sizes, separating by air flow, immersing the obtained primary battery cathode material in a citric acid aqueous solution containing a surfactant, washing, and drying to obtain the impurity-removing material.
  7. 7. The green regeneration method of the bio-based carbon coated waste lithium battery anode material is characterized in that the dispersion grinding parameters in the step S3 are ‌ ball-material ratio (5-10) 1, revolution speed of a planetary ball mill is 300-600rpm, rotating arm speed is 600-1200rpm, and grinding time is 3-5h.
  8. 8. The green regeneration method of the bio-based carbon coated waste lithium battery anode material according to claim 1, wherein the spray drying parameters in the step S3 are 150-180 ℃ of air inlet temperature and 85-100 ℃ of air outlet temperature for 10-30min.
  9. 9. The green regeneration method of the bio-based carbon coated waste lithium battery anode material is characterized in that parameters of carbonization and repair in the step S3 are that the carbonization temperature is 780-820 ℃, the heat preservation is 3-4h, and the temperature rising rate is 3-5 ℃ per minute.
  10. 10. The green regeneration method of the bio-based carbon coated waste lithium battery anode material according to claim 1, wherein the specific process of the step S4 is as follows: Immersing the carbonized material in the hydrolysate of the silane coupling agent, fully and uniformly mixing until the coupling agent is fully grafted on the surface of the carbonized material, drying to obtain the surface modified carbonized material, uniformly mixing the surface modified carbonized material with a boron source, drying, doping at 800-900 ℃ at a temperature rising rate of 2-3 ℃ per minute, preserving the heat for 3-4 hours, cooling to below 150 ℃, and crushing to obtain the boron doped bio-based carbon coated regenerated anode material.

Description

Environment-friendly regeneration method for waste lithium battery anode material coated with bio-based carbon Technical Field The application relates to the field, in particular to a green regeneration method of a waste lithium battery anode material coated by bio-based carbon. Background In recent years, with the rapid development of the electric automobile industry and the continuous updating of vehicles, a great number of retired lithium ion power batteries are generated in the market every year. The retired batteries contain abundant reusable resources, and the resources can be reasonably recycled, so that the recycling of the resources can be realized, the pressure of resource shortage can be effectively relieved, the problem of environmental pollution caused by random disposal can be avoided, and the retired batteries have important significance for ecological environment protection. Therefore, the battery recycling industry has grown and gradually becomes an important branch of the environmental protection and resource utilization fields. Although the recovery of high-value metal elements has been advanced in the industry at present, the regeneration of the anode material cannot be paid enough attention due to factors such as lower added value and higher process complexity. However, in the long term, the realization of full-component closed-loop recycling including the negative electrode material has important and positive effects which are not negligible for improving the resource utilization rate of the whole battery industry, reducing the industrial carbon emission and promoting the sustainable development of the industry. The method is not only beneficial to enterprises to reduce production cost and improve market competitiveness, but also accords with the green development concept advocated worldwide at present, and has profound strategic significance for coping with climate change and protecting the earth environment. Conventionally, for a negative electrode material containing a large amount of impurities recovered from a lithium ion battery, two main means have been generally employed in the industry for the purpose of purification and repair. One is a chemical method, typically acid washing, in which a specific chemical solution reacts with impurities to remove the impurities, and the other is a physical method, in which high-temperature heat treatment is more common, and the impurities are decomposed or volatilized by means of high temperature. In order to further improve the performance of the repaired anode material, such as increasing the multiplying power, prolonging the cycle life and the like, the prior art also often carries out carbon coating treatment on the purified graphite, and most of the coating materials are petroleum-based products such as phenolic resin, asphalt, epoxy resin and the like. These materials can improve the performance of the anode material to some extent, but also expose many problems in practical application. Most importantly, when the phenolic resin of petroleum-based products is used for carbon coating treatment, the preparation and use processes of the phenolic resin are usually carried out without organic solvents for dispersion and dilution, and the organic solvents have volatility, so that the phenolic resin not only can pollute the air environment, but also has potential safety hazards in production, and easily causes safety accidents such as fire and explosion. In addition, these coatings are themselves non-renewable petroleum derivatives, and the use of large amounts is counter to the current "low carbon and environmental friendly" industry upgrade direction, which is detrimental to sustainable development. Finally, in the coating process, the organic resin is uneven in dispersion, so that the continuity of the coating layer is poor and the thickness is uneven, the overall conductive network and the structural stability of the anode material are seriously affected, the performance of the repaired anode material is difficult to reach an ideal state, and the use requirement of a high-performance battery cannot be met. Disclosure of Invention The application aims to overcome the technical problems and provides a green regeneration method of a waste lithium battery anode material coated with bio-based carbon. A green regeneration method of a waste lithium battery cathode material coated with bio-based carbon is prepared by the following steps: s1, raw material pretreatment, namely disassembling and classifying the waste lithium battery anode material to obtain a battery anode material; s2, removing foreign matters, namely removing impurities from the battery cathode material to obtain an impurity-removed material; s3, coating and carbonizing, namely mixing the impurity removing material with the bio-based carbon source coating material, and performing dispersion grinding, spray drying and carbonization repairing to obtain a carbonized material; s4, modi