Amorphous nanoscale antimony-vanadium oxide: A high capacity anode material for potassium ion batteries

Antimony (Sb)-based materials, as a kind of potential high capacity and low cost materials, are the focus of attention in the anode materials of potassium ion batteries. However, at present, studies on Sb-based anode materials mainly focus on Sb metal, Sb alloy and Sb chalcogenides, while reports on Sb-based oxides are relatively rare. In addition, the development of Sb-based materials is limited by their large volume variation and poor reaction kinetics for potassium storage. Herein, a novel amorphous Sb2VO5 (A-SbVO) as bimetallic antimony vanadium oxide has been synthesized by solvothermal method. The A-SbVO exhibits high K storage activity and capacity due to its nanoscale and amorphous structure. Moreover, ex-situ transmission electron microscopy and X-ray photoelectron spectroscopy revealed the evolution of the A-SbVO in the potassium storage process as follows: A-SbVO → Sb → K3Sb → Sb → Sb + Sb2VO5. After compounding with reduced graphene oxide (rGO), the as-prepared A-SbVO/rGO shows better K storage stability, with discharge specific capacities of 313.0 and 248. 8 mAh/g at 500 and 1000 mA g−1, respectively. After 300 cycles at 200 mA g−1, the A-SbVO/rGO still has a high discharge specific capacity of 382.1 mAh/g.