MnO2电极在水系电解液中电容性能的研究

采用溶胶0凝胶法制备出了纳米MnO2，通过X射线衍射试验表明产物是具有双链结构的α-MnO2。在3种浓度接近饱和的水系电解液：中性，强碱性，弱酸性中进行充放电测试。测试结果表明，Mn02电极在0．5mol／L K2SO4溶液中电位窗口只有0．3V，且比容量很低，仅有10．2F／g；在7．0mol／LKOH溶液中电位窗口达到1．0V，电容量为120．3F／g；在2．0mol／L（NH4）2SO4中电位窗口为0．4V，比容量可以达到94.6F／g。

Research on the capacitive performance of MnO2 electrode in different aqueous electrolytes

In this paper, an nano-sized MnO2 was prepared by sol-gel method. XRD had been used to characterize the performance of the materials. Results of X-ray diffraction showed that the phase of nano-MnO2 powder prepared was of α-MnO2. The measurement of constant current discharge and cyclic voltammogram tests were performed and compared in three different solutions, The results were that the maximum capacitance of MnO2 electrode was only 10.2 F/g and the voltage was only 0.3 V with 0.5 mol/ L K2SO4. But the capacitance reached to 120.3 F/g, and the voltage was 1.0 V with 7.0 mol/L KOH. The capacitance and the voltage were respectively 94.6 F/g and 0.4V with 2.0 mol/L （NH4）2SO4.