电解质浓度和温度对活性炭电容性能的影响(英文)

Influence of Electrolyte Concentration and Temperature on the Capacitance of Activated Carbon

采用循环伏安、交流阻抗和恒流充放电技术考察了电解质浓度和温度对活性炭电容性能的影响.活性炭电容器在0.1、0.5、1.0和6.0mo·lL-1KOH溶液中性能测试结果表明:活性炭在高浓度电解质中具有高电容和低内阻,但电位窗口较窄;电容和内阻与KOH浓度的对数成正比.活性炭电容在不同温度(20、40、80°C)的性能测试结果表明:高温能够增加电容和降低内阻,但是却加速了长期充放电过程中电容的衰减.

The influences of electrolyte concentration and temperature on the capacitive behavior of activated carbon（AC） were investigated by cyclic voltammetry,electrochemical impedance spectroscopy,and galvanostatic charge/discharge measurements.The performance of a symmetric capacitor was characterized in 0.1,0.5,1.0,and 6.0 mol·L-1 KOH solution.We found that the high electrolyte concentration led to high capacitance,low internal resistance,and a narrow voltage window.The capacitance and internal resistance were found to be linearly dependent on the logarithm of KOH concentration.AC supercapacitor performance was investigated at 20,40 and 80 °C,respectively.We found that elevated temperatures are favorable for an increase in capacitance and for a decrease in internal resistance.However,elevated temperatures increase the capacitance fading rate during long charge/discharge cycling tests.