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 of recycling lithium ion batteries comprising:
obtaining solid battery components from lithium ion batteries;
separating charge materials from the solid battery components, the charge materials including charge material metals of one or more of Ni, Mn, and Co;
leaching the charge materials to obtain a solution with a first pH of a first pH range to precipitate impurities from the solution;
adding one or more metal salts to the solution, the metal salts having metal cations corresponding to the charge material metals, and adjusting a relative ratio of the charge material metals in the solution to a selected ratio; and
precipitating a cathode material precursor from the solution, the cathode material precursor having the selected ratio.
2. The method of claim 1 , wherein leaching the charge materials to obtain the solution includes adding one or more of an acid and a reducing agent.
3. The method of claim 1 , further comprising:
precipitating the cathode material precursor as a metal hydroxide form of the charge material metals to generate precipitated metal hydroxides, and
combining the precipitated metal hydroxides with a lithium salt to form a cathode material.
4. The method of claim 3 , wherein a ratio of Ni:Mn:Co in the cathode material precursor corresponds to the selected ratio of the charge material metals in the solution.
5. The method of claim 1 , wherein precipitating the cathode material precursor includes increasing a pH of the solution to a second pH of a second pH range, the second pH higher than the first pH by at least twofold.
6. The method of claim 5 wherein the first pH range is based on an ability to precipitate impurities including one or more of iron and copper while leaving the charge material metals in solution.
7. The method of claim 5 wherein the second pH range is based on an ability to precipitate hydroxides of the charge material metals.
8. The method of claim 5 wherein the first pH range is between 3-5 and the second pH range is between 10 and 13.
9. The method of claim 1 , further comprising maintaining the temperature of the solution below 80° C. during coprecipitation of the cathode material precursor.