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

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 Co 3 O 4 at high temperature, and the nano-octahedral Co 3 O 4 shows excellent cyclability and rate capacity as an anode electrode for LIBs owing to its nano-size. In addition, the recycled materials (nano-Co 3 O 4 and Li 2 CO 3 ) can be converted to LiCoO 2 with a significantly reduced particle size and an excellent layered structure, and it shows better electrochemical performance than commercial LiCoO 2 . 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. A LIB recycling technology based on a controllable product morphology and excellent performance was reported. We constructed a "cycle-fail-regeneration" new closed-loop utilization model of waste LIBs. Through this mode, waste materials can be regenerated in situ for LIB anode materials, providing multiple reuse scenarios. Density functional theory calculation is used to analyze the transformation mechanism of this process and provide theoretical support.