无定型MnO2的合成及电化学性能研究

以KMnO4、MnCl2和KOH为原料利用液相化学共沉淀法制备了MnO2电极材料，通过X-射线衍射、扫描电子显微镜、比表面积分析、热重分析、循环伏安法和恒流充放电等测试手段对所合成材料的物理性质和电化学性能进行了表征.研究结果表明:该材料为无定型结构α-MnO2，比表面积高达90 m2·g-1，在0.5 mol·L-1 Li2SO4电解液中的电势窗口为0～0.8 V（vs.SCE），在扫描速率为1 mV·s-1时的比电容高达110.2 F·g-1，漏电流为0.117 mA，经500次充放电后仍有良好的循环稳定性.

The Preparation and Electrochemical Performance of Amorphous MnO2

MnO2 as electrode material for supercapacitors was synthesized with chemical coprecipitation method by using KMnO4 ,MnCl2 and KOH aqueous solution as raw materials. Physical and electrochemical characterization of the synthesized material were performed using XRD,SEM,BET,TG/DTG,cyclic voltammograms and galvanostatic charge-discharge and so on. Results showed the obtained α-MnO2 had a amorphous structure and BET specific sur-face areas are 90 m2 ·g-1 . The specific capacitance of the amorphousα-MnO2 was 110. 2 F·g-1 in 0. 5 mol·L-1 Li2SO4electrolyte at the scan rate of 1 mV·s-1 in the range of 0 ~0. 8 V(vs. SCE)and leakage current of the MnO2 electrode was 0. 117 mA,exhibiting excellent cycling behavior in 500 cycles of charge-discharge.