廉价模板法制备介孔MnO_2的电化学电容性质

Electrochemical capability of mesoporous manganese dioxide prepared by cheap template method

以国产嵌段共聚物P123为模板剂制备了介孔氧化硅模板KIT-6,利用"反相复制法"制备出具有介孔结构的二氧化锰电极材料。BET测试结果表明,所制备KIT-6和二氧化锰的BET比表面积分别为821.7m2/g和137m2/g,孔径分布分别集中在2.67nm和3.67nm,其孔容分别为0.52cm3/g和0.39cm3/g。循环伏安,交流阻抗以及恒电流充放电测试表明用所制介孔二氧化锰制备的电极有很好的电化学电容性能,首次放电容量可达295F/g,远高于直接分解Mn(NO3)2所制得的MnO2,并且其复平面图表现出典型的电容特征。因此,采用该法制备的这种介孔结构的MnO2能够用来制作电化学电容器电极,并且保持较高的比电容量和良好的电容性能。

Mesoporous SiO2 template KIT-6 was synthesized using cheap domestic P123 as template agent, and the mesoporous MnO2 was prepared by ＂inverse phase duplicate method＂. The testing results showed that the BET specific surface area of as-prepared template and mesoporous MnO2 reached 821.7 m^2 and 137 m^2/g respectively. Their aperture distributions concentrated on 2.67 nm and 3.67 nm, and the pore volumes were 0.52 cm^3/g and 0.39 cm^3/g respectively. Good electrochemical capability of the asprepared mesoporous MnO2 was testified by cyclic voltammetry, electrochemical impedance spectra, as well as constant current charge/discharge experiment. It was found that the first specific discharge capacity reached 295 F/g, much higher than that of the MnO2 prepared by decomposing Mn （NO3）2 directly. Moreover, it showed typical capacity characterization in Nyquist plots. As a result, such prepared mesoporous MnO2 could be used to fabricate the supercapacitor electrode and maintain high specific capacitance and good capacitive behavior.