Method and apparatus for recycling lithium-ion batteries
Cathode material from exhausted lithium ion batteries are dissolved in a solution for extracting the useful elements Co (cobalt), Ni (nickel), Al (Aluminum) and Mn (manganese) to produce active cathode materials for new batteries. The solution includes compounds of desirable materials such as cobalt, nickel, aluminum and manganese dissolved as compounds from the exhausted cathode material of spent cells. Depending on a desired proportion, or ratio, of the desired materials, raw materials are added to the solution to achieve the desired ratio of the commingled compounds for the recycled cathode material for new cells. The desired materials precipitate out of solution without extensive heating or separation of the desired materials into individual compounds or elements. The resulting active cathode material has the predetermined ratio for use in new cells, and avoids high heat typically required to separate the useful elements because the desired materials remain commingled in solution.
1. A method for obtaining a cathode material with a selected ratio of metallic elements from recycled battery electrode materials, comprising:
leaching the metallic elements from the recycled battery electrode materials with a solution including sulfuric acid and a reducing agent, the solution having a pH within a pH range;
adjusting concentrations of the metallic elements to the selected ratio using additional quantities of the metallic elements, the additional quantities sourced from refined materials; and
adjusting the pH to acidic levels for removing impurities and to basic levels to precipitate the metallic elements for the cathode material.
2. The method of claim 1 wherein the refined materials include metal sulfates.
3. The method of claim 1 , wherein adjusting the pH to the acidic levels includes increasing the pH of the solution to a first, acidic pH to precipitate the impurities, and wherein adjusting the pH to the basic levels includes increasing the pH of the solution to a second, basic pH.
4. The method of claim 3 , wherein increasing the pH of the solution to the second, basic pH includes increasing the pH at least two times higher than the first, acidic pH.
5. The method of claim 4 wherein the second, basic pH is between 10.5-13.0.
6. The method of claim 4 , wherein the first, acidic pH is between 3-5 based on an amount of iron in the solution for precipitating Fe(OH) 3 .
7. The method of claim 4 , wherein the first, acidic pH is less than 7 for precipitating Cu from the solution.
8. The method of claim 4 , wherein the selected ratio of metallic elements includes one or more of Ni, Mn, Co as Ni x Mn y Co z (OH) 2 where x, y and z represent molar ratios of the respective metallic elements.
9. The method of claim 4 , wherein the pH for leaching the metallic elements is lower than the first, acidic pH.