Urchin-like alkaline nickel–cobalt carbonate derived Ni3S4/Co3S4 nanoparticles anchored on rGO for lithium/sodium-ion batteries with enhanced capacity

Abstract

Transition metal sulfides (TMS) have emerged as promising anode materials for lithium and sodium ion batteries due to their high theoretical capacity and low cost. However, the severe volume expansion during the conversion reaction causes rapid collapse inevitability when used as anode material. Herein, we pertinently fabricated nanoscale Ni3S4/Co3S4 with uniform particle size homogeneously dispersed between pleated graphene (Ni3S4/Co3S4@rGO) through facile hydrothermal assisted by cationic surfactants. The construction of 3D nanocomposites significantly shortens ion migration distances and enriches electronic pathways, accelerating charge transfer kinetics while maintaining good stability. Uniformly distributed bimetallic sulfides and rGO limit each other's aggregation, allowing the excellent structural properties of the material to be maintained over time. Thus, the Ni3S4-Co3S4@rGO electrodes deliver a high reversible capacity of 972.5 mAh/g upon 200 cycles at 100 mA g−1 in Lithium-ion battery and 487.5 mAh/g upon 150 cycles at 100 mA g−1 in Sodium-ion battery, as well as excellent rate capacity in both. These excellent properties show the potential for expansion of this simple synthetic method in the field of alkali metal batteries.