High Capacitance of Electrodeposited MnO[sub 2] by the Effect of a Surface-Active Agent

Manganese dioxide has been electrochemically deposited on a Ni substrate from a neutral electrolyte in the presence of a surface-active agent, namely, sodium lauryl sulfate (SLS), for supercapacitor application. The potentiodynamically prepared oxide provides higher capacitance than the potentiostatically and galvanostatically prepared oxides. Owing to adsorption of the surfactant molecules at the interface during electrodeposition, the manganese dioxide possesses higher specific surface area. Specific capacitance of 310 F g − 1 obtained for the oxide prepared in the presence of SLS over an extended charge-discharge cycling is higher by about 25% in relation to the oxide prepared in the absence of SLS.