Effects of surface modification on electrochemical performance of MnO2
(1. Department of Chemistry, Zhejiang University, Hangzhou 310027, China;
2. State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, China)
2. State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, China)
Abstract: The MnO2 samples coated with Ca(OH)2 were prepared by a liquid-phase surface treatment method. The physical properties of the samples were examined by SEM, EDAX and chemical analysis, and their electrochemical performances were investigated by means of galvanostatic charge-discharge, cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The SEM results show that the samples coated with Ca(OH)2 display a porous surface structure. The electrochemical experiments indicate that the surface modification decreases the polarization of MnO2 electrodes and improves their discharge potentials and discharge capacities.
Key words: manganese dioxide; surface modification; cyclic voltammetry; electrochemical impedance spectroscopy