High capacity supercapacitor material based on reduced graphene oxide loading mesoporpus murdochite-type Ni6MnO8 nanospheres

Abstract

Mesoporous materials often deliver a series of attractive properties for low-cost and environmentally-friendly energy storage/conversion technologies. Based on this, we prepared mesoporous murdochite-type Ni6MnO8 nanospheres (NMN) with a uniform morphology by using a template route. Then as-prepared NMN were loaded uniformly on reduced graphene oxide (RGO) sheets via electrostatic interaction to fabricate RGO-NMN composite (RGO-NMN), which combines the advantages of both RGO such as double-layer capacity and NMN such as high pseudocapacitity. By the aid of a nanosized mesoporous silica template, NMN and RGO-NMN display a large specific surface areas and concentrated pore diameter distribution. The large surface area and abundant pores can provide a promising route for easy access of electrolyte in energy storage electrodes and favor the availability of Faradic reaction in electroactive sites greatly. Indeed, following electrochemical analysis uncovered a remarkable value of specific capacitance (862.5Fg−1 and 498.3Fg−1 at 0.5Ag−1 for RGO-NMN and NMN) and a predominant long-term stability with slight decays less than 10% after 9000 cycling test in both NMN and RGO-NMN electrodes.