Selective Lithium Recovery from Spent Lithium-Ion Battery Leachate by 3D Evaporative Crystallization

Rising demand for lithium (Li) driven by lithium-ion battery (LIB) proliferation underscores the importance of sustainable recycling. Conventional processes for recovering Li from spent LIB leachate are energy-intensive or chemically demanding, compromising the environmental and economic viability. This study introduces an ecofriendly approach using capillary-driven three-dimensional (3D) evaporative crystallization within a porous cotton matrix. Low-solubility salts (CoCl2, MnCl2, and NiCl2) crystallize proximally, while highly dissolvable LiCl migrates toward the distal zone, achieving spatial separation on the crystallizer. Maximum selectivity reached 109.5 (Li/Co), 7.8 (Li/Ni), and 3.2 (Li/Mn) in the simulated leachate, corresponding to a 4.7-fold enrichment of Li abundance. A comparable selective Li separation was demonstrated for a real leachate, confirming the practical potential of the approach. The natural-physiochemical-process-induced 3D evaporative crystallization eliminates high energy or chemical inputs, providing a sustainable and low-cost pathway for selective Li recovery from variable spent LIB leachates.