Graphite Regeneration and NCM Cathode Type Synthesis from Retired LIBs by Closed-Loop Cycle Recycling Technology of Lithium-Ion Batteries

Abstract

A closed-loop regeneration process for spent LiCoO2 has been successfully designed with prior synthesis of LiNixCoyMnzO2, by the authors. This research applies the methodology to lithium-ion battery anodes, using spent graphite from a decommissioned battery in a leaching process with 1.5 mol∙L−1 malic acid and 3% H2O2 alongside LiCoO2. The filtered graphite was separated, annealed in an argon atmosphere, and the filtrate was used to synthesize NCM cathode material. Characterization involved X-ray diffraction, EDX, and SEM techniques. The regenerated graphite (RG) showed a specific discharge capacity of 340.4 mAh/g at a 0.1C rate in the first cycle, dropping to 338.4 mAh/g after 55 cycles, with a Coulombic efficiency of 99.9%. CV and EIS methods provided further material assessment. In a related study, the SNCM111 synthesized from the leaching solution showed a specific discharge capacity of 131.68 mAh/g initially, decreasing to 115.71 mAh/g after 22 cycles.