Chronoamperometric Versus Galvanostatic Preparation of Manganese Oxides for Electrochemical Capacitors

Abstract

Chronoamperometric and galvanostatic methods of manganese dioxide electrodeposition have been compared in this work for their ability to produce high specific capacitance manganese dioxide electrodes for supercapacitor applications. When directly compared in terms of the charge passed (and hence the mass of manganese dioxide deposited) and the timeframe of electrodeposition, chronoamperometry most often led to superior performing electrodes. In the best case, an electrode was prepared that attained 2986 F/g. The results of this work were interpreted in terms of the manganese dioxide deposition mechanism and its impact on deposit morphology. Furthermore, it was concluded that the loss of charge during electrodeposition, as either the result of Mn 3þ intermediate species diffusing away from the electrode, or the competing oxygen evolution process, significantly influenced the ability to estimate the amount of manganese dioxide prepared.

Morphology and composition control of manganese oxide by the pulse reverse electrodeposition technique for high performance supercapacitors

“…21 It is well known that the CP method produces MnO 2 . 19,22 In the case of the PP and PRP methods, two peaks were observed at slightly lower binding energies at 641.8 and 653.5 eV, respectively. It is generally accepted that the binding energy of Mn 2p for Mn 2 O 3 is lower than that of MnO 2 .…”

Electro-precipitation via oxygen reduction: a new technique for thin film manganese oxide deposition

“…40 nm. 20,21 As a consequence composite systems look very promising. They combine the good conductivity from materials such as graphene, gold, carbon nanotubes, etc.…”

Structural and electrochemical properties of MnO2-Carbon based supercapacitor electrodes

“…Since the fast redox-charge storage in MnO x was identified to take place mainly on the surface of the material, efforts were focusing on optimized structural design of hybrid electrodes [6]. Such approaches range from simply mixing carbon as a conductive agent, MnO x and a binder [7][8][9], to thin film deposition [10,11] and templating [12,13]. Alternatively, electrolytic deposition of MnO 2 into (activated) microporous carbon xerogels, as suggested by several groups, e.g.…”

“…Alternatively, electrolytic deposition of MnO 2 into (activated) microporous carbon xerogels, as suggested by several groups, e.g. Cross et al [10], will employ the micropores at the surface of the primary particles and therefore increases the total amount of MnO 2 available for charge storage. A promising approach based on electrodeposition was recently published by Lin et al.…”