Preparation of coal-based graphene quantum dots/α-Fe2O3 nanocomposites and their lithium-ion storage properties

Nano-Fe2O3 particles on a nickel substrate have been obtained by electrodeposition technique adjusting the ratio of electrolyte solvent (DMF and water), and then it was used as the working electrode to obtain the C-GQDs/α-Fe2O3 composite material via second-step electrodeposition with the coal-based graphene quantum dots (C-GQDs) solution which had been prepared from Taixi anthracite powder as the electrolyte. The lithium-ion storage performance of C-GQDs/α-Fe2O3 composites as the anode in the lithium-ion battery was studied, and the results show that the composites exhibited excellent cyclability and rate capability. When the current density was 1 A/g, the specific capacitance of C-GQDs/α-Fe2O3 composites was up to 1582.5 mAh/g, and it could maintain 1320 mAh/g after 110 cycles. The specific capacitance was 1091 mAh/g at a high current density (5 A/g).