Fabrication and Characteristics of Galvanostatic Electrodeposited MnO2 on Porous Nickel from Etched Aluminium

Abstract

A porous hybrid electrode was fabricated by electrodepositing manganese oxide on porous electroformed nickel from anodized etched aluminium. With increasing deposition current densities, the manganese oxide electrode changed from porous and fibrous to a denser film. The electrochemical characteristics of the MnO2 electrode are closely related to the mass loading, morphology and scan rate. At the same mass loading, a higher areal and specific capacitance was obtained for MnO2 film with a denser structure at a higher deposition current density and a low scan rate (for example, 10mV s−1). A high volumetric capacitance (200 F cm−3) and large areal capacitance (0.9 F cm−2), as calculated from cyclic voltammetry at a scan rate of 1mV s−1, were obtained for the hybrid electrodes at a deposition current density of 10mAcm−2 for 10min. The present hybrid electrodes also showed good cycling stability (almost no reduction after 1000 cycles at a scan rate of 10mV s−1).