Boosting the Performance Enhancement of Short-Process Regenerated Ni-Rich Cathode Via Antimony Doping and Modification

Abstract

Currently, the short-process regeneration of cathode materials in spent lithium-ion batteries has attracted wide attention from researchers because of its short process flow, less waste liquid discharge and the cascade utilization of recycled materials. However, the performance of short-process regenerated electrode materials is generally difficult to comparable with the commercial materials, especially for lithium nickel cobalt manganese oxide (NCM). Herein, antimony (Sb) doping, and modification is proposed to boost the performance enhancement of short-process regenerated NCM in our work. Spent NCM was first selectively leached by oxalic acid, and then directly dried to obtain the precursor without separation and filtration. Finally, NCM was regenerated by lithium supplement and Sb doping modification. The regenerated NCM with optimal Sb doping modification (R-Sb10) has better electrochemical performance and cycle stability. It delivers an initial specific discharge capacity of 152.3 mAh/g, and the capacity retention maintains 86.3% after 200 cycles at 0.5C, which can be comparable to the commercial NCM. The Sb element can be evenly distributed in the interior of short-process regenerated NCM, especially with a protective Li3SbO4 film on the surface. Through theoretical calculation, the R-Sb10 has a lower energy for material formation, higher energy barrier for cation disorder and decreasing diffusion energy barrier for Li+. The doping modification method can be put into production to meet the practical needs and provide a new idea for improving the properties of regenerated materials.

Keywords: lithium-ion batteries, Recycling of spent batteries, Selective leaching, Short-process regeneration, Doping and modification