Preparation and characterization of manganese oxide microelectrodes for microelectromechanical system supercapacitor

Abstract

The capacity of charge storage for supercapacitor depends on the size of the electrode surface area and the active material on the electrodes. In this article, we fabricate the three-dimensional microelectrodes with SU-8 photoresist based on the microelectromechanical system technology to increase the electrode surface area and to carry more active materials on the electrodes. The three-dimensional microelectrode was directly prepared by the method of anodic electrodeposition. Its surface and composition were characterized by scanning electron microscopy and energy dispersive spectroscopy. Moreover, cyclic voltammetry and galvanostatic charge-discharge current are also used to test the electrochemical characteristics of the manganese oxide electrodes. When the discharge density is 0.5 mA cm 22 , the areal capacitance for the fabricated three-dimensional microelectrodes with microstructure and the two-dimensional planar microelectrodes without microstructure is 3.68 mF cm 22 and 1.0 mF cm 22 , respectively. The experimental results show that the three-dimensional microelectrode structure prepared with microelectromechanical system technology can effectively increase the electrode surface area and carry more electroactive materials, thereby enhancing the charge storage capacity of the electrodes.

Recent progress in micro-scale energy storage devices and future aspects

“…36,140 Since its rst application as an electrode material, MnO 2 has shown promising and signicant applications in energy storage devices due to its high theoretical capacitance of 1370 F g À1 , 24 non-toxic nature and low cost as well. 41,141 Jiang et al used the composite of MnO 2 and MWCNTs for the fabrication of 3D microelectrodes for application in on-chip MSCs. 142 3D microelectrodes were fabricated on silicon wafers by the combination of spin-coating, photolithography, pyrolysis, and electrochemical deposition techniques.…”