The regeneration of natural stibnite with introduced oxide-based catalyst towards enhanced Li-storage properties

Abstract

Owing to its excellent theoretical specific capacity, Sb₂S₃ captures widespread attention in the energy-storage field. However, it still suffers from volume expansion and sluggish electrochemical kinetics. Meanwhile, considering serious pollution and complex chemical preparation processes, stibnite is regarded as “first-hand” materials, displaying enormous energy-storage application potential; however, it is still limited by low-purity and high crystallinity. Herein, stibnite is purified and regenerated through physical chemical and vacuum gas-phase melting strategy to form high-properties stibnite-based electrode materials. Assisted by the introduction of lithium nitrate as an active medium, abundant sites and effective structural traits are formed, effectively promoting the reversibility of electrochemical kinetic processes. Utilized as lithium-ion battery anodes, the as optimized samples have a capacity of approximately 656.8 mAh g⁻¹ with a capacity retention rate of 89.9 % at 0.5 A g⁻¹. Even at 5.0 A g⁻¹, the capacity of 483.3 mAh g⁻¹ could be remained after 100 cycles. Supported by a detailed kinetic analysis, the enhancement of the surface-controlling behavior and the reduction of capacitive resistance are confirmed. Herein, the as-regenerated phase and the introduced oxide-based catalyst are beneficial to alleviate polysulfide shuttling and volume expansion, further accelerating ion/electron transfer behaviors. This work is expected to shed light on strategies to design promising mineral-based anodes for lithium-ion batteries.