Synthesis of Ni-doped NiO/RGONS nanocomposites with enhanced rate capabilities as anode materials for Li ion batteries

Abstract

Ni-doped NiO–reduced graphene oxide nanosheet (RGONS) nanocomposites as anode materials for Li ion batteries are synthesized through a solvothermal and calcination method. The obtained Ni-doped NiO–RGONS nanocomposites display an improved cycling stability (682 mA h g⁻¹ in the 45th cycle at 200 mA g⁻¹) and an enhanced rate capability (530 mA h g⁻¹ at 1000 mA g⁻¹). NiO–RGONS nanocomposites with a similar structure and RGONS content can also be obtained when the calcinations are performed under air conditions, but they can only keep 292 mA h g⁻¹ and 117 mA h g⁻¹ at 200 mA g⁻¹ and 1000 mA g⁻¹, respectively. The high electrochemical performances of the as-prepared Ni-doped NiO–RGONS nanocomposites could be attributed to their unique structure, in which the highly dispersed Ni NPs have some catalytic effects and improve the electronic conductivity. Also, the layered structure of the NiO nanoplates and RGONSs prevents the aggregation of NiO and decreases the stacking of the RGONSs.