Uniform-dispersed ZnS quantum dots loading on graphene as a promising anode for potassium-ion batteries

The uniform-dispersed and morphology-controllable ZnS quantum dots loading on graphene nanosheets were investigated as an anode material for PIBs. By combining the smaller volume expansion and shorter ion diffusion distance of ultra-nano ZnS quantum dots (∼2.8 nm) with the higher conductivity of rGO, the ZnS QDs-rGO anode displayed the splendid stable capacity of 122 mAh/g at a current density of 1 A/g over 500 cycles.