介孔-C/MnO2非对称超级电容器的研究

以氧化硅介孔分子筛SBA-15为模板制备出介孔MnO2和介孔炭, 并分别作为正极和负极在6 mol·L-1 KOH电解液中组装出新型非对称超级电容器. 小角X射线衍射(LXRD)、透射电镜(TEM)以及N2吸附-脱附测试表明样品具有介孔结构, 且比表面积较大, 孔径分布范围较窄. 采用恒流充放电、循环伏安、交流阻抗等电化学方法考察了非对称超级电容器的性能. 在0.1 A·g-1电流密度、不同充放电电位下进行研究, 得出最佳充放电电位为1.8 V. 结果表明, 在0.1 A·g-1电流密度、1.8 V的充放电电位下电容器的充放电性能良好, 等效串联电阻(ESR)为1.15 Ω, 功率密度为89.0 W·kg-1, 能量密度达31.3 Wh·kg-1, 首次放电比容量为76.7 F·g-1, 经过1000次循环容量仍保持在69.5 F·g-1.

Study on Meso-C/MnO2 Asymmetric Supercapacitors

Mesoporous MnO2 and mesoporous carbon were prepared using silica mesoporous molecular sieves (SBA-15) as a hard template. A meso-C/MnO2 asymmetrical supercapacitor was assembled and characterized in 6 mol·L-1 KOHelectrolyte. Low X-ray diffraction (LXRD), transmission electron microscopy (TEM), and nitrogen adsorption-desorption results indicated that the as-prepared samples had mesoporous structures, large specific surface areas, and a narrow pore diameter distribution range. Galvanostatic charge/discharge, cyclic voltammetry, and AC (alternating current) impedance were used to investigate the electrochemical performance. At 0.1 A·g-1 current density, different potentials were applied to obtain the optimum cell voltage of 1.8 V. Under this condition, the supercapacitor exhibited good charge/discharge capacities. Results showed that the equivalent series resistance (ESR), power density, and energy density were 1.15 Ω, 89.0 W·kg-1, and 31.3 Wh·kg-1, respectively. The initial specific capacitance was 76.7 F·g-1 and 69.5 F·g-1 was obtained after 1000 cycles.