Solvothermal Synthesis of Ni/Reduced Graphene Oxide Composites as Electrode Material for Supercapacitors

•Ni/RGO composites were successfully synthesized through a simple solvothermal method.•The attached Ni nanoparticles can efficiently inhibit the aggregation of RGO nanosheets and provide pseudocapacitance.•Ni/RGO–2 exhibits the highest specific capacitance of 547.3 F g−1 at 1 A g−1 in 2 M KOH.•Ni/RGO–2 can maintain 81% of initial capacity after a continuous 1000 times of cycling.

A series of Ni/reduced graphene oxide (Ni/RGO) composites were synthesized through a simple solvothermal method. Detailed characterizations of the composite using transmission electron microscopy and field emission scanning electron microscopy indicated that Ni particles were uniformly dispersed on the RGO surfaces. The electrochemical performances of Ni/RGO composites were much higher than their counterparts of Ni and RGO, because of the Ni particles being firmly decorated with the RGO nanosheets and the synergistic effect between both components. Among the prepared composites, Ni/RGO–2 exhibits the best electrochemical performance; namely, a high specific capacitance of 547.3 F g−1 is obtained in 2 M KOH at 1 A g−1 and 81% of initial value is remained after a continuous cycling of 1000 times, which make it to be a promising electrode material for supercapacitors.