稳定且宽电位窗口的掺铁二氧化锰超级电容器材料

Fe-doped manganese dioxide for stable wide-potential-window supercapacitors

利用简单的液相沉淀法制备出不同掺杂铁含量的二氧化锰超级电容器材料,旨在改善二氧化锰材料的电位窗口及稳定性。通过XRD、SEM和BET对其结构和形貌进行了表征,同时在中性电解液中采用循环伏安曲线(CV)、充放电曲线(PT)、循环性能测试、大电流充放电测试以及交流阻抗测试研究了其电化学性能。结构和形貌表征结果显示Mn/Fe-2.0具有较优的晶体结构和多孔特性,电化学测试结果显示Mn/Fe-2.0在中性电解质中表现出最好的电容性能,比电容可达489F/g,比未掺杂的纯二氧化锰材料提高了22%,同时具备稳定且宽的电位窗口,是超级电容器比较理想的正极材料。

Fe-doped manganese dioxide were synthesized via a simple liquid-phase process in order to improve its potential-window and stability. The phase structure, morphology, and size of the prepared manganese dioxide were characterized by using X-ray diffraction, scanning electron microscopy, and N2 adsorption-desorption isotherm and the electrochemical properties of the Fe-doped manganese dioxide were investigated by cyclic voltammetry (CV), galvanostatic charge-discharge (PT), cyclic performance test, the high-rate discharge ability and alternating current (AC) impedance spectroscopy. The structure and morphology measurements showed Mn / Fe-2.0 were porous and had good crystal structure. Electrochemical measurements confirmed Mn/Fe-2.0 had the best capacity in neutral electrolytes, and its specific capacitance reached 489F / g, which increased by 22% compared to that of pure manganese dioxide. Therefore, Mn/Fe-2.0 could be an ideal anode material with a wide-potential-window and good cycling stabilities for supercapacitors.