Sodium ion storage in reduced graphene oxide

The performance of few-layered metal-reduced graphene oxide (RGO) as a negative electrode material in sodium-ion battery was investigated. Experimental and simulation results indicated that the as-prepared RGO with a large interlayer spacing and disordered structure enabled significant sodium-ion storage, leading to a high discharge capacity. The strong surface driven interactions between sodium ions and oxygen-containing groups and/or defect sites led to a high rate performance and cycling stability. The RGO anode delivered a discharge capacity of 272 mA h g−1 at a current density of 50 mA g−1, a good cycling stability over 300 cycles and a superior rate capability. The present work provides new insights into optimizing RGOs for high-performance and low-cost sodium-ion batteries.