Mesoporous carbon–manganese oxide composite as negative electrode material for supercapacitors

3D-assembles of silica spheres were used as hard template to synthesize porous carbon materials with large mesopores to be included as current collectors in supercapacitors and developing large surface areas reaching up to 900 m2/g. Birnessite-type MnO2 was deposited by a co-precipitation method in the porous network. Electrochemical performances of resulting MnO2/C nanocomposites were evaluated by cyclic voltammetry and showed an initial capacitance and a retained capacitance after 500 cycles for the nanocomposite at 6 wt% MnO2 in C of about 660 and 490 F/g, respectively.