Three-dimensional flower-like nickel oxide supported on graphene sheets as electrode material for supercapacitors

Dispersed three-dimensional (3D) flower-like nickel oxide on graphene sheets was synthesized by incorporating a facile hydrothermal process with a thermal treatment process. The possible growth mechanism of 3D flower-like NiO is discussed. When used as electrode materials for supercapacitors, the resultant composite exhibits a specific capacitance of 346F/g (1.5A/g), a good rate performance and cycle stability in 2 M KOH. NiO in the composite could provide a specific capacitance as high as 778.7F/g, compared to that of bare NiO of only 220F/g. The functional features of unique 3D flower-like NiO morphology, high conductivity of graphene sheets and its protective effect to the structure of NiO result in an improved electrochemical performance.