Recycling LiCoO2 with methanesulfonic acid for regeneration of lithium-ion battery electrode materials

With the massive consumption of lithium-ion batteries in portable consumer electronics and electric vehicles, proper disposal of spent batteries is of paramount importance for sustainable development. In this study, biodegradable organic methanesulfonic acid (MSA) is investigated for the first time to leach valuable metals from waste LiCoO2 powders for battery material regeneration. Under the optimal conditions, leaching efficiencies of lithium and cobalt are achieved at nearly similar to 100% and similar to 100%, respectively. Comparison experiment indicates that MSA can achieve better leaching performance than previously reported organic acids (e.g. citric acid, malonic acid, succinic acid, oxalic acid) under the same conditions. Besides, strong leaching capability of MSA at high solid-to-liquid ratios (e.g. 81.2 g L-1 and 163 g L-1) is confirmed with satisfactory leaching efficiencies (ca. 92.4%-100%). Feasibility test of MSA utilization for proper treatment of spent batteries is demonstrated at the optimized conditions. Importantly, regeneration study suggests that the as-obtained leachate can be employed to synthesize Co3O4 anode and LiCoO2 cathode materials with micro/nanostructures. Excellent cycling performance and rate capability of the regenerated electrode materials are demonstrated in the repeated charge-discharge cycles. Overall, the proposed recycling strategy is of great significance for rational resource utilization of spent lithium-ion batteries.