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CN-122010195-A - Regeneration method and application of waste ternary cathode material

CN122010195ACN 122010195 ACN122010195 ACN 122010195ACN-122010195-A

Abstract

The invention provides a regeneration method and application of a waste ternary positive electrode material. The preparation method comprises the following steps of S1, mixing and reacting the waste single crystal and polycrystal mixed ternary positive electrode material with an oxidant in an alkaline aqueous solution system with the pH value of 12.5-14 and the temperature of 25-50 ℃ to obtain an oxide precursor, wherein the surface of the oxide precursor is of a layered NiOOH structure, the morphology of the oxide precursor is single crystal particles, S2, adding a lithium source and doped metal salt into the alkaline system to react to obtain a doped lithium intercalation positive electrode material precursor, and S3, annealing the doped lithium intercalation positive electrode material precursor at high temperature to obtain the doped modified regenerated single crystal positive electrode material. The invention realizes the surface structure reconstruction and bulk phase lattice repair of the waste ternary cathode material under mild conditions, has simple process flow and uniform lithium supplementing and doping, and the obtained regenerated cathode material has good structural stability and electrochemical performance, and is suitable for the field of recovery and regeneration of lithium ion battery cathode materials.

Inventors

  • YUAN LIXIA
  • Hao Shuaipeng

Assignees

  • 华中科技大学

Dates

Publication Date
20260512
Application Date
20260309

Claims (10)

  1. 1. The regeneration method of the waste ternary cathode material is characterized by comprising the following steps of: S1, mixing and reacting a waste ternary anode material with an oxidant in an alkaline system with the pH of 12.5-14 and the temperature of 25-50 ℃ to obtain an intermediate formed by primary particles; the surface of the primary particles is of a layered NiOOH structure; the D50 of the primary particles is 0.5-1 mu m; The molecular formula of the intermediate is Li 1-a Ni b Co c Mn d O 2 , wherein 0< a <1, 0.3≤b≤ 0.9,0.05≤c≤ 0.3,0.05≤d≤0.3, b+c+d=1; S2, adding a lithium source and doped metal salt into the alkaline system to react to obtain a doped lithium intercalation anode material precursor; S3, annealing the obtained doped lithium intercalation positive electrode material precursor at a high temperature to obtain the regenerated single crystal positive electrode material with the doped modified D50 of 2-5 mu m.
  2. 2. The method for regenerating a waste ternary cathode material according to claim 1, wherein in the step S1, na 2 CO 3 is added, and the addition amount of Na 2 CO 3 is 0.01-0.1 mol/L.
  3. 3. The method for regenerating a waste ternary positive electrode material according to claim 1, wherein the molar ratio of Li 1-a Ni b Co c Mn d O 2 to the oxidant in the waste ternary positive electrode is 1:0.5-2.5.
  4. 4. The method for regenerating the waste ternary cathode material according to claim 1, wherein in the step S1, the mixing reaction time is 1-48 h, and the solid-liquid mass volume ratio of the waste ternary cathode material to the alkaline aqueous solution is 1-10 g/mL.
  5. 5. The method for regenerating the waste ternary cathode material according to claim 1, wherein in the step S2, the reaction time is 1-48 h, the reaction temperature is 80-200 ℃, and the reaction pressure is 0.1-2.0 MPa.
  6. 6. The method for regenerating a spent ternary positive electrode material according to claim 1, wherein the lithium source comprises a soluble lithium salt; the soluble lithium salt includes at least one of lithium acetate, lithium sulfate, lithium nitrate, and lithium hydroxide.
  7. 7. The method for regenerating a waste ternary cathode material according to claim 1, wherein the doped metal salt comprises at least one of Na, mg, K, al or Ca.
  8. 8. The regeneration method of the waste ternary cathode material according to claim 1, wherein the molar ratio of the doping element in the doping metal salt to the total metal element in the intermediate formed by the primary particles is 0.001-0.05:1.
  9. 9. The method for regenerating the waste ternary cathode material according to claim 1, wherein in the step S3, the high-temperature annealing temperature is 650-900 ℃, the high-temperature annealing time is 8-20 h, and the high-temperature annealing atmosphere is air or pure oxygen atmosphere.
  10. 10. Use of the regenerated single crystal ternary cathode material prepared by the method according to any one of claims 1-9 in lithium ion batteries.

Description

Regeneration method and application of waste ternary cathode material Technical Field The invention belongs to the technical field of lithium ion battery recycling, and particularly relates to a regeneration method and application of a waste ternary cathode material. Background Lithium ion batteries have been widely used in the fields of portable electronic devices, electric vehicles, large-scale energy storage power stations, and the like because of their advantages such as high energy density, high operating voltage, long cycle life, and the like. In recent years, the installed amount of power lithium ion batteries is continuously increased and the market scale is continuously enlarged under the promotion of the rapid development of new energy automobile industry. However, as early power batteries gradually enter a retired period, the problems of disposal and recycling of waste lithium ion batteries are increasingly severe, and development of efficient, green and economic recycling technologies is urgently needed. In a positive electrode material system of a lithium ion battery, nickel-cobalt-manganese ternary oxide (NCM for short) has become a mainstream positive electrode material because of high specific capacity and relatively controllable cost. The high-nickel ternary material further improves the energy density by improving the nickel content, but the cycle stability and the thermal safety of the high-nickel ternary material are relatively poor. In the long-term charge and discharge or storage process, the material is easy to have the problems of lithium loss, cation mixing and discharge, surface structure collapse, bulk lattice defect accumulation and the like, so that the electrochemical performance is obviously attenuated. At present, the recovery treatment of the waste ternary cathode material mainly adopts three technical routes, namely (1) a pyrometallurgical method, namely, burning out organic components through high-temperature smelting or burning, and recovering metal alloy. The method has simple process, extremely high energy consumption, is easy to generate toxic gases such as dioxin, cannot retain the crystal structure of the original positive electrode material, and cannot realize direct recycling. (2) The hydrometallurgy method is to completely leach Ni, co, mn, li metal elements in the positive electrode material by adopting strong acid and a reducing agent, and then re-synthesize the precursor and the positive electrode material through the steps of extraction separation, coprecipitation and the like. Although the metal recovery rate is high, the process flow is long, the reagent consumption is large, the waste liquid treatment cost is high, the metal loss exists in multi-step operation, and the overall economy and environmental friendliness are limited. (3) The direct regeneration method aims at recovering the electrochemical performance of the waste anode material by supplementing lithium and repairing the structure on the premise of not damaging the layered structure of the main body of the material. The method has the advantages of short flow, low energy consumption, material closed-loop utilization and the like, and is regarded as a most promising green recovery path. However, the existing direct regeneration technology still has obvious defects of high energy consumption due to the fact that lithium is supplemented by relying on high-temperature solid phase reaction, particle sintering or phase change is easy to occur, doping modification elements are difficult to uniformly embed into crystal lattices to cause incomplete structural repair, and the lack of effective activation means on a surface degradation layer and the lack of cooperativity between lithium compensation and crystal lattice reconstruction, so that the capacity recovery rate and the cycle stability of the regenerated material are still lower than those of an original material. In summary, the prior art has not solved the key difficulties of how to efficiently activate the surface of the waste ternary cathode material, synchronously realize lithium compensation and doping modification, and complete high-quality lattice reconstruction under mild conditions. Therefore, there is a need to develop a direct regeneration method with mild process conditions, precise structural repair, sufficient performance recovery and industrial feasibility. Disclosure of Invention The invention aims to develop a regeneration method of a waste ternary cathode material, and aims to solve the problems of complex treatment, uneven lithium supplement, incomplete structural repair and the like in the existing regeneration process of the waste ternary cathode material. In order to achieve the above purpose, the invention provides a regeneration method of waste ternary cathode materials, which comprises the following steps: S1, mixing and reacting a waste ternary anode material with an oxidant in an alkaline system with the pH of 12.5-14 and