CN-122029661-A - Impurity management for recycled cathode materials

Abstract

The recycling of the lithium ion battery includes the step of leaching a black material comprising cathode and anode materials with a leaching agent (optionally comprising an oxidizing agent or a reducing agent) to form an acidic aqueous leach solution of metal salts comprising metal salts and a plurality of impurity salts. These impurity salts are removed in different purification stages, including treatment with an oxygen-containing gas and optional electrodeposition and ion exchange steps, each of which is carried out at a specified pH range. The amount of metal salt in the treated acidic aqueous leaching solution is then adjusted to the desired ratio and co-precipitated to form the precursor cathode active material.

Inventors

• Eric Gallazzi
• Jin Jican
• Amir nazari
• Bebel Villar

Assignees

• 升腾元素公司

Dates

Publication Date

20260512

Application Date

20240815

Priority Date

20230824

Claims (20)

1. 1. A method for producing a cathode material precursor, the method comprising: leaching the black material from the recycled lithium ion battery stream with a leaching agent to obtain an acidic aqueous leaching solution of metal salts comprising nickel salts, cobalt salts, manganese salts, lithium salts and various impurity salts, The acidic aqueous leaching solution is filtered to remove insoluble materials, Reducing the amount of the plurality of impurity salts in the filtered aqueous acidic leaching solution by electrodeposition, by ion exchange, by treating the filtered aqueous acidic leaching solution with an aqueous base and an oxygen-containing gas and removing insoluble materials, or a combination thereof, Adjusting the amount of the metal salts in the reduced impurity aqueous acid leach solution to form an adjusted aqueous acid leach solution, and The metal salts are co-precipitated from the conditioned acidic aqueous leach solution.
2. 2. The method of claim 1, wherein the leaching agent comprises sulfuric acid.
3. 3. The method of claim 1, wherein the leaching agent comprises an oxidizing agent or a reducing agent.
4. 4. The method of claim 3, wherein the oxidizing agent or the reducing agent is hydrogen peroxide.
5. 5. The method of claim 1, wherein the black material is heat treated prior to leaching with the aqueous acid, and wherein the leaching agent does not comprise an oxidizing or reducing agent.
6. 6. The method of claim 1, wherein the filtered acidic aqueous leaching solution is treated with an aqueous base and an oxygen-containing gas and insoluble materials are removed prior to adjusting the amount of the metal salts.
7. 7. The method of claim 6, wherein the plurality of impurity salts comprises copper salts, aluminum salts, or iron salts, and wherein treating the filtered acidic leach aqueous solution with the aqueous base and the oxygen-containing gas reduces the amount of the copper salts, the aluminum salts, or the iron salts.
8. 8. The method of claim 6, wherein the treated acidic aqueous leaching solution has a pH of 5.5 to 6.5.
9. 9. The method of claim 1, wherein the plurality of impurity salts comprises a copper salt, and wherein the amount of the copper salt is reduced by electrodeposition.
10. 10. The method of claim 9, wherein the filtered acidic aqueous leach solution has a starting pH of 5 to 6 prior to electrodeposition and an ending pH of 3.5 to 4.5 after electrodeposition.
11. 11. The method of claim 1, wherein the plurality of impurity salts comprises a calcium salt or a magnesium salt, and wherein the amount of the calcium salt or the magnesium salt is reduced by ion exchange.
12. 12. The method of claim 11, wherein the filtered acidic aqueous leach solution has a starting pH of 3.5 to 4.5 prior to ion exchange and an ending pH of 2.5 to 3.5 after ion exchange.
13. 13. The method of claim 11, wherein ion exchange comprises passing the filtered acidic aqueous leaching solution through a column comprising a dialkylphosphonic acid impregnating resin.
14. 14. The method of claim 6, wherein the plurality of impurity salts comprises zinc salts, and wherein the amount of zinc salts is reduced by ion exchange.
15. 15. The method of claim 14, wherein the filtered acidic aqueous leach solution has a starting pH of 2.5 to 3.5 prior to ion exchange and an ending pH of 1.5 to 2.5 after ion exchange.
16. 16. The method of claim 15, wherein ion exchange comprises passing the filtered acidic aqueous leaching solution through a column comprising a [ bis (2-ethylhexyl) hydrogen phosphate impregnating resin.
17. 17. The method of claim 1, wherein reducing the amount of the plurality of impurity salts removes less than 10% of the nickel salt, the cobalt salt, or the manganese salt.
18. 18. The method of claim 1, wherein after reducing the amount of the plurality of impurity salts, the pH of the impurity reduced acid leach aqueous solution is <4, and wherein the method further comprises increasing the pH of the impurity reduced acid leach aqueous solution to a pH >4 prior to adjusting the amount of the metal salts.
19. 19. A method for producing a cathode material precursor, the method comprising: the black material from the recycled lithium ion battery stream is heat treated, Leaching the heat treated black material with a leaching agent to obtain an acidic aqueous leaching solution of a metal salt comprising a nickel salt, a cobalt salt, a manganese salt, a lithium salt and a plurality of impurity salts, wherein the leaching agent does not comprise an oxidizing agent or a reducing agent, The acidic aqueous leaching solution is filtered to remove insoluble materials, Treating the filtered acidic aqueous leach solution with an aqueous base and an oxygen-containing gas and removing insoluble material, Adjusting the amount of the metal salts in the treated aqueous acid leach solution to form an adjusted aqueous acid leach solution, and The metal salts are co-precipitated from the conditioned acidic aqueous leach solution.
20. 20. A method for producing a cathode material precursor, the method comprising: leaching the black material from the recycled lithium ion battery stream with a leaching agent to obtain an acidic aqueous leaching solution comprising nickel salts, cobalt salts, manganese salts, lithium salts and metal salts of various impurity salts, and the pH of the acidic aqueous leaching solution is <1, The acidic aqueous leaching solution is filtered to remove insoluble materials, Treating the filtered acidic aqueous leach solution with an aqueous base and an oxygen-containing gas and removing insoluble material, wherein the treated acidic aqueous leach solution has a pH >5, Reducing the amount of the plurality of impurity salts in the treated aqueous acid leach solution by electrodeposition, ion exchange, or both, wherein the pH of the treated aqueous acid leach solution is reduced to 2 to 4, Increasing the pH of the treated aqueous acid leach solution to >4 and adjusting the amount of the metal salts in the treated aqueous acid leach solution to form an adjusted aqueous acid leach solution, and The metal salts are co-precipitated from the conditioned aqueous solution.

Description

Impurity management for recycled cathode materials Background Lithium ion (Li ion) batteries are a preferred chemistry for secondary (rechargeable) batteries in high discharge applications such as Electric Vehicles (EVs) and power tools that require rapid motor acceleration. Li-ion batteries include a charge material, conductive powder, and a binder applied to or deposited on a current collector of a typical ground plane copper or aluminum sheet. The charging material comprises an anode material, typically graphite or carbon, and a cathode material comprising a predetermined ratio of metals such as lithium, nickel, manganese, cobalt, aluminum, iron and phosphorus, thereby defining the so-called "battery chemistry" of the Li-ion battery cell. Lithium ion battery recycling is intended to recover charging material from depleted or spent lithium ion battery cells (cells). Other battery materials, such as lithium and carbon (graphite), may also be recovered. Recycling typically involves physical grinding and breaking of old battery packs from the recycling stream (typically from a scrapped EV). The result is a particulate black material comprising mixed cathode material metals (such as Ni, mn and Co) and anode materials (such as graphite). Other materials (such as copper, iron, and aluminum) are typically present in residual amounts, which are impurities resulting from grinding and comminution of the battery. The recycling process includes leaching the black material to recover the charging material metal in pure form. However, eliminating all impurities can be difficult. Disclosure of Invention Purification or impurity removal of mixed particulate matter of cathode and anode materials involves air bubbling of a leaching solution obtained by leaching the particulate matter with an acidic leaching agent such as sulfuric acid. The progressive sequence of purification stages includes a pH change of the target impurity, which enables incremental removal of the impurity. Specifically, after the initial leaching stage, each purification stage reaches a continuously decreasing pH, until a final stage in which ratio adjustment of the cathode material metal and co-precipitation of the charge material precursor at a prescribed ratio occurs. Thus, leaching of the mixed particulate matter begins at a relatively low pH (typically below 1 based on the leaching acid). The pH of the leach solution was increased to about 6.0 with air sparging followed by a continuous decrease in pH at each stage of removal of the target impurity. After purification and ratio adjustment of cathode material metal for co-precipitation of precursor cathode active material (p-CAM), the pH is raised again. The configuration herein is based in part on the observation that a spent lithium ion battery, such as from electric and hybrid vehicles (EVs), still contains a significant amount of charging material metal in its battery. Unfortunately, the conventional approach to recovering and recycling spent or depleted Li-ion batteries suffers from the disadvantage that recycling tends to introduce impurities from the housing, current collector, and other materials from the complete battery installed in the donor vehicle. Physical disassembly, crushing and grinding of the battery pack and the contained battery cells results in mixed particulate matter of battery materials. These impurities may have a negative impact on the resulting recycled battery from the recycle stream. Accordingly, the configurations herein substantially overcome the disadvantages of impurities in Li-ion battery recycle streams by progressively purifying the leach solution of recycled battery material to remove a variety of impurity types of impurities to produce a substantially pure cathode material precursor comprising a charging material metal such as Ni, mn and Co for use as an active cathode material in a recycled battery. In a particular configuration, a method for producing a cathode material precursor or p-CAM includes leaching a black material from a recycled lithium ion battery stream with an aqueous acid to obtain an acidic aqueous leach solution (leach solution) of a metal salt comprising a nickel salt, a cobalt salt, a manganese salt, a lithium salt, and a plurality of impurity salts. Filtering the leaching solution to remove insoluble materials, and treating the filtered leaching solution with an aqueous base and an oxygen-containing gas to remove specific dissolved metal salt impurities as a precipitate. Optionally, further purification may be provided, including electrodeposition and/or ion exchange, followed by removal of specific target dissolved impurity salts. The amount of metal salt in the treated acidic aqueous leach solution is adjusted to form an adjusted leach solution in a prescribed ratio, and then the metal salt is co-precipitated from the adjusted leach solution. Drawings The foregoing and other features will be apparent from the following description of part