Recovery and regeneration of ternary cathode materials through Solid-State reactions

The recycling of spent LiNixCoyMnzO2 (NCM) not only alleviates the issue of lithium resource scarcity, but also ensures the sustainable development of lithium-ion batteries in industry. However, traditional metal extraction techniques from spent NCM often require high energy consumption or tedious separation and purification processes. In this work, we propose a hybrid pyro-hydrometallurgy method to selectively recover lithium from spent NCM811 through solid-state reaction with oxalic acid, enabling both the preferential extraction of lithium with a high recovery efficiency of 95.7 %, and the synthesis of ternary oxide precursors. Then NCM811cathode material is directly regenerated from the remaining ternary oxide. The regenerated NCM811cathode material delivers a discharge capacity of 183.3 mAh g- 1 (0.1C) and a capacity retention of 60.4 % after 200 cycles at 1C, which are comparable to those of commercial NCM811. This work provides a scalable strategy to achieve the closed-loop recycling of NCM cathode with high recovery efficiency and low cost.