Abstract
The current Na+ storage performance of carbon-based materials is still hindered by the sluggish Na+ ion transfer kinetics and low capacity. Graphene and its derivatives have been widely investigated as electrode materials in energy storage and conversion systems. However, as anode materials for sodium-ion batteries (SIBs), the severe pi-pi restacking of graphene sheets usually results in compact structure with a small interlayer distance and a long ion transfer distance, thus leading to low capacity and poor rate capability. Herein, partially reduced holey graphene oxide is prepared by simple H2O2 treatment and subsequent low temperature reduction of graphene oxide, leading to large interlayer distance (0.434 nm), fast ion transport, and larger Na+ storage space. The partially remaining oxygenous groups can also contribute to the capacity by redox reaction. As anode material for SIBs, the optimized electrode delivers high reversible capacity, high rate capability (365 and 131 mAh g(-1) at 0.1 and 10 A g(-1), respectively), and good cycling performance (163 mAh g(-1) after 3000 cycles at a current density of 2 A g(-1)), which is among the best reported performances for carbon-based SIB anodes.