Separation of cobalt and lithium from spent LiCoO2 batteries using zeolite NaA and the resulting ion exchange product for N2/O2 separation

Abstract

As a common material used in lithium-ion batteries, LiCoO2 has both environmental and economic benefits due to its recyclability (key metals: Co and Li). Hydrometallurgy, a common method used to recover metal ions, is still facing challenges in terms of the effective and simple recovery of metal ions from the leaching solution. In this work, a new method of separating Co2+ and Li+ from the leaching solution of spent LiCoO2 using zeolite has been proposed. As a result, NaA zeolite exhibited the highest Co2+/Li+ separation selectivity in the Co-Li (1:1) mixed solution, reaching > 95% Co2+ removal, while all Li+ remained in the solution. In addition, CoNaA, a product separated from the Co-Li mixed solution by NaA zeolite, has been tested for its N2 and O2 adsorption properties; the N2/O2 selectivity (80/20, v/v) was up to 5.3 and the breakthrough experiment results demonstrated its excellent N2/O2 separation performance. Overall, ion exchange using NaA zeolite is a promising method used to separate Co2+ and Li+ from a LiCoO2 leaching solution and the exchange products can be used as an adsorbent for N2/O2 separation.