Porous NiO/Ag composite film for electrochemical capacitor application

A highly porous NiO/Ag composite film is prepared by the combination of chemical bath deposition and silver mirror reaction. The as-prepared NiO/Ag composite film has an interconnecting reticular morphology made up of NiO flakes with highly dispersed Ag nanoparticles of about 6 nm. The pseudocapacitive behavior of the NiO/Ag composite film is investigated by cyclic voltammograms (CV) and galvanostatic charge-discharge tests in 1 M KOH. The NiO/Ag composite film exhibits weaker polarization, higher specific capacitance and better cycling performance as compared to the unmodified porous NiO film. The specific capacitance of the porous NiO/Ag composite film is 330 Fg(-1) at 2 A g(-1) and 281 Fg(-1) at 40 A g(-1), respectively, much higher than that of the unmodified porous NiO film (261 Fg(-1) at 2 A g(-1) and 191 F g(-1) at 40 A g(-1)). The enhancement of pseudocapacitive properties is due to highly dispersed Ag nanoparticles in the composite film, which improves the electric conductivity of the film electrode. (C) 2010 Elsevier Ltd. All rights reserved.