A novel method to prepare Sb/graphene composite with high capacity for potassium-ion batteries

•Sb/graphene composite contains low content of Sb (9.2 wt%) and few-layer graphene.•The composite is prepared by hydrothermal reaction plus high-temperature calcination.•The composite has high capacity (601.4mAh/g at 100 mA/g) and better cycle performance.•Synergetic effect of Sb and graphene is the key to better electrochemical properties.