Fabrication of a hierarchical NiO/C hollow sphere composite and its enhanced supercapacitor performance.

A hierarchical NiO/C hollow sphere composite (NiO/C-HS) was prepared via semi-sacrificial template-assisted hydrothermal and calcination methods. NiO/C-HS, with well-dispersed NiO nanosheets supported by carbon hollow spheres, exhibited excellent electrochemical performance. The method was heuristic for the design of other composites and suitable for ameliorating the poor stability of transition metal oxides.