MnO2电沉积直立碳纳米管制备超级电容器的研究

以直立碳纳米管为基底，以pH=6.0的0.1mol/L Na2SO4 为底液，采用电化学沉积法在0.2 mol/L Mn(CH3COO)2溶液中制备了直立碳纳米管与二氧化锰复合材料。SEM测试结果表明复合材料表面呈现多孔状结构。通过循环伏安，恒流充放电，交流阻抗等电化学方法对复合材料修饰电极进行电容性质测试。实验结果表明，在1mol/L KCl 溶液中，0-0.6V(vs. 银/氯化银参比)电位窗口内此复合材料表现出优良的超电容性能。直立碳纳米管电极的比电容为16 F/g，在碳纳米管表面沉积上二氧化锰修饰层后，此复合材料电极的比电容增大至330 F/g，比电容量大幅提升近20倍。同时扫描200圈后，直立碳纳米管与二氧化锰复合材料的循环伏安曲线变化很小，说明其具有相当好的循环寿命和电容稳定性能。

The supercapacitors of manganese oxide-modified aligned carbon nanotube nanocomposite by electrodeposition method

MnO2 thin film was electrodeposited onto aligned carbon nanotubes (ACNTs) electrode in the electrolyte containing 0.2 mol/L Mn(CH3COO)2 and 0.1mol/L Na2SO4 at pH 6.0. As observed by scanning electron microscopy, the resulting MnO2 film on those nanotubes is hole-like microstructure. Such-prepared MnO2-modified ACNTs nanocomposite was then characterized by cyclic voltammograms, charge-discharge curve and electrochemical impedance measurements etc., and it performed excellent capacitive behavior between 0-0.6v (versus Ag/AgCl) in 1mol/L KCl aqueous solution. The specific capacitance of the ACNT electrode was calculated at 16F/g before the MnO2 film modification, and then it increased to 330 F/g after the MnO2 film deposition due to the special Faradic capacitance of MnO2 With scaning for 200 cycles, there’s a litter change for its cyclic voltammogram curve, indicating the good reversible and capacitive property for the MnO2-ACNTs composite.