US 12,463,266 B2
Graphite recovery in recycled batteries
Eric Gratz, Worcester, MA (US); and Zhangfeng Zheng, Worcester, MA (US)
Assigned to Ascend Elements, Inc., Westborough, MA (US)
Filed by Battery Resourcers LLC, Worcester, MA (US)
Filed on Jun. 8, 2021, as Appl. No. 17/341,616.
Claims priority of provisional application 63/036,066, filed on Jun. 8, 2020.
Prior Publication US 2021/0384563 A1, Dec. 9, 2021
Int. Cl. H01M 10/54 (2006.01); C22B 3/00 (2006.01); C22B 7/00 (2006.01); C22B 47/00 (2006.01); H01M 4/133 (2010.01); H01M 4/583 (2010.01); H01M 10/0525 (2010.01)
CPC H01M 10/54 (2013.01) [C22B 7/007 (2013.01); C22B 23/043 (2013.01); C22B 47/0063 (2013.01); H01M 4/133 (2013.01); H01M 4/583 (2013.01); H01M 10/0525 (2013.01)] 24 Claims
OG exemplary drawing
 
1. A method for recycling graphite from a recycling stream of exhausted Li-ion batteries, consisting of:
receiving a comingled Li-ion battery recycling stream of dismantled Li-ion batteries including both cathode and anode materials;
leaching of cathode charge materials from the comingled Li-ion battery recycling stream with an aqueous acid leach; and
generating a precipitate comprising graphite and impurities comprising alumina and metal sulfates from the aqueous acid leach;
wherein, after the aqueous acid leach of the cathode charge materials, a mixture is formed by adding a strong acid to the generated precipitate for removal of the impurities, the strong acid resulting in a pH lower than a pH of the precipitate-generating acid leach;
heating the mixture at a temperature between 250° C. and 350° C.; and
washing the generated precipitate for removal of water soluble contaminants to generate purified graphite.