Lithium recovery and solvent reuse from electrolyte of spent lithium-ion battery

Great progresses have been made in recovering valuable metals or regenerating materials from spent lithium-ion batteries (LIBs), but how to treat the spent electrolyte and recover its valuable components economically are still a bottleneck. In this study, the volatile organic solvents (dimethyl carbonate (DMC) and diethyl carbonate (DEC)) in spent electrolyte were recycled through vacuum distillation based on thermodynamic analysis and reused for LIBs. The recovery efficiencies of DMC and DEC reach almost 100% and 79.40%, respectively, under the distillation temperature of 130 °C for 120 min. The prepared electrolyte by recovered DMC and DEC shows high discharge capacity and good cycle performance (discharge capacity retention is over 99% after 400 cycles at 1C) by Li/graphite battery. Moreover, lithium left in non-volatile components (ethylene carbonate (EC)) was recovered as lithium carbonate (purity is 92.45%) with a recovery efficiency of 86.93%. The proposed process sheds light on the comprehensive recycling of electrolyte from spent LIBs.