A lithium-ion battery recycling technology based on a controllable product morphology and excellent performance

Abstract

Recycling spent lithium-ion batteries (LIBs) is the most effective way to solve the associated problems of ecological damage and resource depletion. However, the focus of recycling technology is mostly waste utilization, and little thought is given to the relationship between the material aging mechanisms and recycling transformation, or the conversion relationship between waste and materials, resulting in low recycling efficiency, a complex process and unavoidable secondary pollution. Here, we report a LIB transformation technology with a controllable product morphology and excellent performance based on the aging mechanisms of scrap cathode materials. Specifically, the failed cathode material is converted to nano-octahedral Co₃O₄ at high temperature, and the nano-octahedral Co₃O₄ shows excellent cyclability and rate capacity as an anode electrode for LIBs owing to its nano-size. In addition, the recycled materials (nano-Co₃O₄ and Li₂CO₃) can be converted to LiCoO₂ with a significantly reduced particle size and an excellent layered structure, and it shows better electrochemical performance than commercial LiCoO₂. Through macroscopic thermodynamics and microscopic kinetics research, the utilization rate of the main atoms of the failed materials can reach 100%, indicating that the recycling process is economically affordable, efficient and environmentally benign.