化学共沉淀法制备超级电容器电极材料MnO_2

Supercapacitor electrode material based on amorphous hydrous MnO_2: preparation and characterization

采用化学共沉淀法制得无定形水合MnO2粉体用于超级电容器电极材料。X射线衍射(XRD)分析结果表明,该样品主晶相为a-MnO2·nH2O。以该粉体作为活性物质制成电极,考察了其电化学性能。循环伏安分析表明,电极在0.5mol·L-1Na2SO4溶液中,-0.2～0.9V(vs.SCE)电位范围内,表现出良好的电容性能,50次循环后其比容量稳定在160F·g-1。以5mA·cm-2电流对MnO2电极做恒流充放电测试,其比容量可达180.2F·g-1,经100次循环,比容量保持率在93%以上。

Amorphous hydrous MnO2 powder used as electrode materials for supercapacitors was synthesized by chemical co-precipitation method. XRD pattern of the resulting power showed that the main crystal structure of the sample was α -MnO2·nH2O. Electrochemical properties of the resultant were investigated by testing the charge/discharge curves and cyclic voltammetry of a three-electrode system, in which working electrode was made from the product, Cyclic voltammograms （vs.SCE） gave ideal capacitor behavior between -0.2 V and 0.9 V in 0.5 mol. L^-1 Na2SO4 with a constant specific capacitance after 50 cycles of about 160 F·g^-1. Electrode made of resultant powder can provide a specific capacitance of 180.2 F·g^-1 at a discharge current density of 5 mA.cm^-2, After 100 cycles, the specific capacitance maintains above 93%.