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CN-122000513-A - Regeneration method of retired lithium battery positive electrode material, regenerated positive electrode material, lithium ion battery and electricity utilization device

CN122000513ACN 122000513 ACN122000513 ACN 122000513ACN-122000513-A

Abstract

The application provides a regeneration method of a retired lithium battery anode material, the regenerated anode material, a lithium ion battery and an electricity utilization device, and relates to the technical field of waste lithium battery recovery. The regeneration method comprises the following steps of calcining a retired positive plate for one time in an oxygen-containing atmosphere to obtain retired positive plate powder, wherein positive active materials in the retired positive plate comprise lithium-containing transition metal phosphate, aluminum element is contained in the retired positive plate powder, mixing the retired positive plate powder with a lithium source, an organic carbon source and a phosphorus source to obtain a mixed material, and performing secondary calcination on the mixed material in a protective atmosphere to obtain the regenerated positive plate material with a carbon/aluminum phosphate mixed coating layer. The regeneration method can remove aluminum-containing impurities and improve the initial discharge gram capacity and the high-temperature cycle performance of the lithium ion battery prepared by the regenerated positive electrode material.

Inventors

  • JIANG RENQIAN
  • WANG SIHUI
  • FENG YUEHAN

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260508
Application Date
20241106

Claims (14)

  1. 1. The regeneration method of the anode material of the retired lithium battery is characterized by comprising the following steps of: Calcining the retired positive plate for one time in an oxygen-containing atmosphere to obtain retired positive plate powder, wherein the positive active material in the retired positive plate comprises lithium-containing transition metal phosphate, and the retired positive plate powder contains aluminum element; Mixing the retired anode powder with a lithium source, an organic carbon source and a phosphorus source to obtain a mixed material; And (3) carrying out secondary calcination on the mixed material in a protective atmosphere to obtain the regenerated positive electrode material with the carbon/aluminum phosphate mixed coating layer.
  2. 2. The regeneration method according to claim 1, wherein the molar ratio of the lithium element, the transition metal element and the phosphorus element in the retired positive electrode powder is (0.7-0.9): (0.98-0.99): 1.
  3. 3. The regeneration method according to any one of claims 1 to 2, wherein lithium in the lithium source is present in the form of ions; And/or the molar ratio of the lithium element to the transition metal element in the mixed material is (1-1.08): 1.
  4. 4. The method of regenerating according to claim 3, wherein said lithium source comprises at least one of lithium carbonate, lithium hydroxide, lithium dihydrogen phosphate, lithium acetate, or lithium oxalate.
  5. 5. The method of regenerating according to any one of claims 1 to 4, wherein the organic carbon source comprises at least one of glucose, sucrose, fructose, polyacrylonitrile, pitch, phenol resin, starch, citric acid, polyvinyl alcohol, or polypropylene; And/or the addition amount of the organic carbon source is 10-15 wt% of the mass of the retired anode powder material.
  6. 6. The regeneration method according to any one of claims 1 to 5, characterized in that the content of aluminum element in the retired positive electrode powder is 500ppm to 2000ppm; and/or, the phosphorus source comprises a phosphoric acid species; And/or the molar ratio of the adding amount of the phosphorus source to the aluminum element in the retired anode powder material is (1-1.1): 1.
  7. 7. The regeneration process of claim 6, wherein the phosphorus source comprises at least one of monoammonium phosphate, diammonium phosphate, phosphoric acid, or lithium dihydrogen phosphate.
  8. 8. The regeneration method according to any one of claims 1 to 7, wherein the temperature of the primary calcination is 350 ℃ to 600 ℃ for 1h to 10h; and/or the volume ratio of oxygen in the oxygen-containing atmosphere is not less than 10%; and/or the temperature of the secondary calcination is 500-750 ℃ and the time is 8-16 h; And/or the protective atmosphere is an inert atmosphere or a reducing atmosphere.
  9. 9. The regeneration method according to any one of claims 1 to 8, wherein the mixing is by ball milling or sand milling; And/or the mixing mode is sanding, wherein the rotational speed of the sanding is 1000 rpm-6000 rpm, and the time is 0.5 h-4 h; and/or the mixing step further comprises spray drying.
  10. 10. The regeneration method according to any one of claims 1 to 9, wherein the lithium-containing transition metal phosphate has a chemical composition LiM x PO 4 , wherein M includes at least one of Fe, co, mn, ni, cu, mg, al, zn, cd, sc, ti, V, cr, Y, la, ce, nd, eu, gd or Tb, and x is 0.5≤1.
  11. 11. The method of regenerating according to claim 10, wherein said lithium-containing transition metal phosphate comprises at least one of lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt phosphate, lithium manganese phosphate, or lithium vanadium iron phosphate.
  12. 12. A regenerated positive electrode material, characterized in that it is prepared by the regeneration method according to any one of claims 1 to 11.
  13. 13. A lithium ion battery comprising the regenerated positive electrode material of claim 12.
  14. 14. An electrical device comprising the lithium-ion battery of claim 13.

Description

Regeneration method of retired lithium battery positive electrode material, regenerated positive electrode material, lithium ion battery and electricity utilization device Technical Field The application relates to the technical field of waste lithium batteries, in particular to a method for regenerating a positive electrode material of a retired lithium battery, the regenerated positive electrode material, a lithium ion battery and an electricity utilization device. Background The lithium battery positive electrode sheet generally comprises an aluminum foil current collector, conductive carbon and a binder, wherein the conductive carbon and the binder can be removed completely by a high-temperature method in the recycling process, but the recycled regenerated positive electrode material inevitably contains a certain amount of aluminum simple substances and aluminum-containing compound impurities, and the presence of the impurities adversely affects the repair and utilization of the positive electrode material, and particularly reduces the initial discharge gram capacity and the high-temperature cycle performance of the regenerated positive electrode material. Disclosure of Invention The present application has been made in view of the above problems, and an object of the present application is to provide a method for regenerating a retired lithium battery positive electrode material, a regenerated positive electrode material, a lithium ion battery, and an electric device, which can remove aluminum-containing impurities and improve electrochemical performance of the regenerated positive electrode material. The first aspect of the application provides a regeneration method of a retired lithium battery positive electrode material, which comprises the following steps of calcining a retired positive electrode plate for one time in an oxygen-containing atmosphere to obtain retired positive electrode powder. Wherein, the positive electrode active material in the retired positive electrode plate comprises lithium-containing transition metal phosphate, and aluminum element is contained in retired positive electrode powder. And mixing the retired anode powder with a lithium source, an organic carbon source and a phosphorus source to obtain a mixed material. And (3) carrying out secondary calcination on the mixed material in a protective atmosphere to obtain the regenerated positive electrode material with the carbon/aluminum phosphate mixed coating layer. In the above technical scheme, the retired positive plate usually comprises an aluminum foil current collector, a positive electrode active material positioned on the surface of the aluminum foil current collector, a binder and conductive carbon, and although the binder and the conductive carbon can be removed to a certain extent by conventional high-temperature treatment, aluminum impurities are inevitably left in the positive electrode powder when the aluminum foil current collector and the positive electrode powder are stripped. In addition, after high-temperature treatment, part of aluminum simple substances are oxidized, aluminum-containing compound impurities such as aluminum oxide and the like are also existed, the aluminum simple substances and the aluminum-containing compound impurities are difficult to remove or use, and the electrochemical performance of the regenerated positive electrode material is also affected. According to the regeneration method of the retired lithium battery anode material, firstly, the retired anode plate is calcined under the oxygen-containing atmosphere, so that conductive carbon, a binder and residual electrolyte can be sufficiently removed, and meanwhile, an aluminum foil current collector and anode powder can be effectively separated to obtain retired anode powder containing aluminum elements. In the retired anode powder, the content of lithium element is relatively less, a certain amount of phosphorus source is added for mixing by adding a lithium source and an organic carbon source, and then secondary calcination is carried out, the lithium source can be used for effectively supplementing lithium to obtain a regenerated lithium-containing transition metal phosphate anode material again, the organic carbon source can form a uniform carbon coating layer on the surface of the regenerated anode material, and meanwhile, the organic carbon source can be used as a reducing agent for inhibiting transition metal ions from being oxidized, so that the composition regulation and control are realized. And the additionally added phosphorus source can react with aluminum-containing compound (such as alumina) impurities to generate aluminum phosphate (or/and aluminum lithium phosphate or/and lithium iron aluminum phosphate), and the aluminum phosphate and carbon are mixed to form a coating layer on the surface of the regenerated positive electrode material particles, so that the transmission rate of lithium ions can be effectively improve