Short process for Li2CO3 synthesis and spent LiCoO2 remediation via Glycine-LiOH slurry electrolysis

Abstract

Effectively recycling spent lithium-ion batteries (S-LIBs) has considerable economic and environmental benefits. In this study, a novel approach for simultaneously synthesizing Li2CO3 and remediating LiCoO2 from S-LIBs via slurry electrolysis is proposed, employing glycine-LiOH as the electrolyte. The operating conditions were optimized to a solid-to-liquid ratio of 20 g/L, slurry electrolysis time of 8 h, current density of 50 mA/cm2, reaction temperature of 80 °C, and glycine concentration of 1.0 mol/L. Li2CO3 was directly synthesized in the anode region, with a purity of up to 99.52 %. Additionally, LiCoO2 was partially remediated in the cathode, increasing Li-Co molar ratio from 0.659 to 0.93. The obtained Li2CO3 and the electrolysis residue LiCoO2 then underwent additional calcination, yielding a layered LiCoO2. At a Li-Co molar ratio of 1.1, the initial specific capacity of the calcined LiCoO2 material was 129.9 mAh/g, exhibiting a capacity retention rate of 50.48 % over 100 cycles. Therefore, a novel, cost-effective, and energy-saving strategy for recycling S-LIBs is proposed.