Supercapacitive properties of a nanowire-structured MnO2 electrode in the gel electrolyte containing silica

Nanowire-structured MnO2 active materials were prepared by a chemical precipitation method and their supercapacitive properties for use in the electrodes of supercapacitors were investigated by means of cyclic voltammetry in an aqueous gel electrolytes consisting of 1 M Na2SO4 and fumed silica (SiO2). The MnO2 electrode showed a maximum specific capacitance of 151 F g−1 after 1000 cycles at 100 mV s−1 when using the gel electrolyte containing 3 wt.% of SiO2, which is higher than 121 F g−1 obtained when using the 1 M Na2SO4 liquid electrolyte alone.