Direct recycling of spent nickel-rich cathodes in reciprocal ternary molten salts.

Lithium-ion batteries (LIBs) have revolutionized portable electronics and electric vehicles (EVs), but the growing accumulation of end-of-life (EOL) batteries poses environmental challenges. Recycling high-value cathodes from EOL LIBs can minimize waste and reduce the need for mining critical minerals. This study focuses on the direct recycling of Ni-rich cathodes, particularly lithium-manganese-cobalt-oxide (NMC) 622 in a "reciprocal ternary molten salts (RTMS)" system. The ionothermal relithiation in the RTMS system successfully restores the layered structure, lithium content, and electrochemical performance of the NMC 622 cathode, comparable to the pristine material. The cost analysis reveals that cathode regeneration through ionothermal relithiation is more economical than virgin production or conventional recycling methods. • A "reciprocal ternary molten salts" (RTMS) system for direct battery recycling. • Directly recycling of spent Ni-rich cathodes by topotactic reactions in RTMS. • A low cost and highly efficient direct recycling process for spent Li-ion batteries. [ABSTRACT FROM AUTHOR]