Electrodes for Electrochemical Supercapacitors

Manganese dioxide nanoparticles were prepared by a chemical precipitation method. Composite electrodes for electrochemical supercapacitors (ES) were fabricated by impregnation of slurries of the manganese dioxide nanoparticles and carbon black into porous nickel foam current collectors. In the composite electrodes, carbon black nanoparticles formed a secondary conductivity network within the nickel foam cells. Obtained composite electrodes, containing manganese dioxide and 0-20 wt% carbon black with total mass loading of 55 mgcm-2, showed a capacitive behavior in the 0.1-0.5 M Na2SO4 solutions. The highest specific capacitance (SC) of 128 Fg-1 was obtained at a scan rate of 2 mVs-1 in the 0.5 M Na2SO4 solutions. The SC increased with increasing carbon black content in the composite materials and increasing Na2SO4 concentration in the solutions and decreased with increasing scan rate.