CN-122029662-A - Impurity control in lithium ion battery recycling

Abstract

A method of producing a cathode material precursor having low levels of Cu impurities is described. Heat treating a black material from the recycled lithium ion battery stream, wherein the black material comprises copper metal and a nickel-containing cathode material, and subsequently leaching the heat treated black material with an aqueous acid solution to form an acidic aqueous leaching solution comprising nickel metal, a cathode metal salt, and a copper salt. It has been found that copper salts react with nickel metal in the aqueous leach solution to form copper metal, which can be readily removed from the acidic aqueous leach solution. The co-precipitation of the cathode metal salt and the nickel salt forms a cathode material precursor that is substantially free of Cu.

Inventors

• Jin Jican
• Eric Gallazzi

Assignees

• 升腾元素公司

Dates

Publication Date

20260512

Application Date

20240815

Priority Date

20230824

Claims (20)

1. 1. A method of producing a cathode material precursor from a recycled lithium ion battery stream, the method comprising: heat treating a black material from the recycled lithium ion battery stream, the black material comprising copper metal and a nickel-containing cathode material; Leaching the heat treated black material with an aqueous acid solution to form an acidic aqueous leaching solution comprising nickel metal and a cathodic metal salt from the cathodic material and a copper salt from the copper metal; reacting the copper salts and the nickel metal in the aqueous leach solution to form copper metal and nickel salts; removing the copper metal from the acidic aqueous leach solution, and The cathode metal salts and the nickel salts are co-precipitated from the acidic aqueous leaching solution to form the cathode material precursor.
2. 2. The method of claim 1, wherein the black material comprises at least 5 weight percent nickel.
3. 3. The method of claim 1, wherein the cathode material comprises 50 mole percent nickel.
4. 4. The method of claim 1, wherein the cathode material further comprises cobalt and manganese.
5. 5. The method of claim 1, wherein the black material is heat treated at a temperature greater than or equal to 500 ℃ for a time between 1 minute and 2 hours.
6. 6. The method of claim 5, wherein the temperature is 550 ℃ to 700 ℃.
7. 7. The method of claim 1, wherein the black material is heat treated in an environment selected from an inert environment, a reducing environment, or a partially oxidizing environment.
8. 8. The method of claim 7, wherein the black material is heat treated in a partial oxidation environment comprising 0.01% to 5% oxygen.
9. 9. The method of claim 1, wherein the black material is heat treated at a solids content of 1 to 80 volume percent relative to the lumen volume of the furnace.
10. 10. The method of claim 1, wherein the heat treated black material comprises nickel metal from decomposition of the cathode material during heat treatment.
11. 11. The method of claim 1, wherein the heat treated black material is leached at a leaching temperature of 20 ℃ to 100 ℃ for a leaching time of 1 to 12 hours.
12. 12. The method of claim 11, wherein the leaching temperature is 70 ℃ to 90 ℃.
13. 13. The method of claim 11, wherein the copper salts and the nickel metal are reacted in the aqueous leaching solution at the leaching temperature.
14. 14. The method of claim 1, wherein the aqueous acid solution comprises a water-soluble acid at a concentration of 25-65 wt%.
15. 15. The method of claim 1, wherein the aqueous acid is sulfuric acid or a combination of sulfuric acid and hydrogen peroxide, and the ratio of liquid (v) to solid (wt) is 0.5-2 v/w%.
16. 16. The method of claim 1, wherein leaching the heat treated black material occurs simultaneously with reacting the copper salts and the nickel metal.
17. 17. The method of claim 1, wherein the acidic aqueous leaching solution comprises a copper salt of less than 100 ppm.
18. 18. The method of claim 1, further comprising water washing the heat treated black material to extract lithium prior to leaching.
19. 19. The method of claim 1, further comprising adjusting the ratio of the cathodic metal salts to a selected ratio with additional metal salts.
20. 20. A method of producing a cathode material precursor from a recycled lithium ion battery stream, the method comprising: heat treating a black material from the recycled lithium ion battery stream at a temperature of greater than or equal to 500 ℃, the black material comprising copper metal and a nickel-containing cathode material, Leaching the heat treated black material with an aqueous acid solution having a water-soluble acid concentration of 25-65 wt% at a leaching temperature of 20 ℃ to 100 ℃ to form an acidic aqueous leach solution; Removing copper metal from the acidic aqueous leach solution, and Co-precipitating a cathodic metal salt and a nickel salt from the acidic aqueous leaching solution to form the cathodic material precursor.

Description

Impurity control in lithium ion battery recycling 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 includes an anode material (typically graphite or carbon) and a cathode material containing a predetermined ratio of metals such as lithium, nickel, manganese, cobalt, aluminum, and iron, thereby defining the so-called "battery chemistry" of the Li-ion battery cell. Li-ion battery recycling seeks to recover charging material from depleted or spent Li-ion battery cells (battery cells). Other battery materials, such as lithium and carbon (graphite), may also be recovered. Recycling typically involves physically dismantling (e.g., grinding or shredding) the old battery pack from the recycling stream (typically from a scrap 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, including copper, iron, and aluminum, may also be present as residual amounts of impurities resulting from grinding and chopping the battery. The recycling process involves leaching the black material to recover the metal of the charging material in pure form. However, it may be difficult to eliminate all impurities. Disclosure of Invention It has been found that heat treating a black material having particulate hybrid materials (including cathode and anode materials) from a Li-ion battery recycle stream facilitates removal of impurities (such as copper) from a subsequent leach stream by promoting the displacement precipitation of copper ions removed from the black material. During the cementation process, copper ions (Cu N+) are reduced to copper metal (Cu 0), which is initiated by downstream separation (leaching) of active metals (e.g., nickel) from the heat treated ferrous material. Specifically, heat treatment of the black material results in reduction of nickel oxide, which is typically a rich component of the black material, to nickel form metal (Ni o). Copper salts leached from the heat treated black material may then be reduced to copper metal by the presence of nickel metal (which has a higher oxidation potential than Cu in the acid leach solution) and may then be subsequently removed. Other impurities such as calcium and magnesium may also be extracted. In this way, co-precipitation of leached active metals such as Ni, mn and Co results in a higher quality charging material for the resulting recycled battery. The configurations herein are based in part on the observation that during typical Li-ion battery recycling, cathode and anode materials from the recycled battery are chopped and ground into a hybrid particulate mixture. Unfortunately, conventional battery recycling methods suffer from the disadvantage that copper flakes and aluminum flakes (typically used for electrodes to which active charging materials adhere) can remain in the mixed particulate matter and other impurities (such as copper) can be generated from the various connections and materials from the battery. These impurities may be difficult to remove. Thus, the configurations herein substantially overcome the disadvantages of residual impurities such as copper in the intermixed particulate admixture by providing for the removal of copper impurities in the presence of Ni metal formed via heat treatment. An example configuration employs NMC (Ni, mn, co) cells for recovering valuable materials from Li-ion cell recycle streams by heat treating black materials from the recycle cell streams, wherein the black materials comprise at least copper metal and Ni-containing cathode materials. The heat treated ferrous material is leached using an aqueous acid solution to form an acidic aqueous leach solution comprising nickel metal and a cathodic metal salt from the cathodic material and a copper salt from the copper metal. In this way, ni metal generated by the heat treatment is leached into an acidic aqueous solution, and at the same time, the leached Cu ions are reduced to Cu metal or the Cu metal is inhibited from being leached into an acidic leaching aqueous solution. The leach solution can then be used to co-precipitate a cathodic metal salt and a nickel salt from the heated acidic leach aqueous solution to form a cathodic material precursor for the recycled NMC battery. Drawings The foregoing and other features will be apparent from the following description of particular embodiments disclosed herein, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead