Synthesis of manganese oxide/activated carbon composites for supercapacitor application using a liquid phase plasma reduction system

Manganese oxide/carbon composite electrode was synthesized using liquid-phase plasma method, to be applied to supercapacitor. Spherical manganese oxide nanoparticles smaller than 10 nm were dispersed uniformly on the surface of YP-50F. The increase in the amount of manganese oxide precipitated on YP-50F resulted in improved specific capacitance, charge–discharge rate, and Warburg impedance but specific surface area and total pore volume were decreased. •Liquid phase plasma process was used to synthesize manganese oxide/carbon composite.•Uniform dispersion of spherical-shaped manganese oxide nanoparticles on the carbon surface.•The quantity of manganese oxide nanoparticle precipitate increased with increasing number of LPP process times.•Repetition of LPP process decreased the specific surface area and total pore volume.•Increase in the quantity of manganese oxide resulted in the improve in the specific capacitance and charge–discharge rate.