Electrochemical Capacitance of Porous Silicon, Carbon, and Manganese(IV) Oxide-Based Composites

The optimum conditions (reaction time and solution concentration) of the deposition of manganese(IV) oxide onto the surface of a porous silicon structure with a carbon coating have been experimentally established. The degree of penetration of the oxide coating into the porous matrix has been determined using Raman spectroscopy. The effect of the additional MnO2 layer on the electrochemical properties of the porous silicon structure with a carbon coating have been determined by cyclic voltammetry and galvanostatic charge‒discharge performance testing. It is shown that the electrochemical capacitance of the electrodes increases to 259 mF/cm2 after the MnO2 deposition. The obtained composites are highly stable: there is no capacitance loss after 20 000 measurement cycles.