超级电容器电极材料——MnO_2的电化学制备及其性能

Studies of electrochemical preparation and performance of MnO_2 for the application of supercapacitor

在25℃,沉积电位为0.50～0.95V条件下,从0.25mol/L醋酸锰溶液中,在石墨电极上沉积出二氧化锰(MnO2)。用扫描电镜(SEM)对所得样品的表面形貌进行了测试,并用循环伏安技术测试了不同沉积电位下制备的二氧化锰电极在不同电解液中的比电容。通过比较不同电解液中的循环伏安行为,发现二氧化锰电极在2mol/LKCl溶液和2mol/L(NH4)2SO4溶液中的循环伏安特性较好,在0.5V下沉积的二氧化锰性能最好。当扫描速度为5mV/s时,其比电容分别为274.74F/g和309.74F/g,并且在2mol/LKCl溶液中电极具有更好的可逆性。

In this paper manganese dioxide was deposited on a carbon substrate a t anodic potentials of 0.50～0.95 V vs. saturated calomel electrode (SCE) in 0.2 5 mol/L Mn(CH3COO)2 solution at 25 ℃. Morphology of MnO2 formed was examined b y SEM technique. The Manganese dioxide formed at different anodic potentials was evaluated by cyclic voltammetry with different potential scan rate in different electrolytes. Results indicate that the pseudocapacitive behaviors of MnO2 are excellent in 2 mol/L KCl solution and 2 mol/L (NH4)2SO4 solution at 25 ℃. MnO2 formed at the anodic potential of 0.5 V showed better capacitive behaviors, 274. 74 F/g in 2 mol/L KCl solution and 309.74 F/g in 2 mol/L (NH4)2SO4 solution. Bet ter reversibility could be got in 2 mol/L KCl solution.