Controllable Growth of Hierarchical NiCo2O4 Nanowires and Nanosheets on Carbon Fiber Paper and their Morphology-Dependent Pseudocapacitive Performances

Hierarchical NiCo2O4 nanowires and nanosheets have been grown on carbon fiber paper (CFP) using a facile solvothermal route allowed by heat treatment. The two morphologies of NiCo2O4 can be easily controlled using solvents with different physicochemical properties (water or metanol) and their pseudocapacitive performances have been evaluated for supercapacitors applications. The results revealed that the CFP supported NiCo2O4 nanosheets exhibits high value of specific capacitance (690 F g(-1)) at current density of 16 A g(-1) and the retained capacitance was 87.1% after 2400 cycles at the discharge current density of 10 A g(-1). The much improved capacity and cycling stability of NiCo2O4 nanosheets may be attributed to the unique hierarchical nanosheets array structures, which has higher specific surface area, providing more sites for the active species and facilitating the fast penetration of electrolyte. Moreover, it also favors better accommodation of strain during the cycle. (C) 2014 Elsevier Ltd. All rights reserved.