煤质活性炭在组装双电层电容器中的电化学性能

Electrochemical Properties of Coal-based Activated Carbons as Electrodes in Electric Double-layer Capacitors

采用恒流充放电、等效串联电阻、漏电流等方法分别测试了优化工艺条件下高比表面积煤质活性炭在水性电解液和有机电解液中的电化学性能。结果表明,煤质活性炭具有优异的能量储存特性、稳定的电化学特性和脉冲性能;在水性和有机电解液中的比电容值分别为204F/g和158F/g;在水性电解液中展示了优异的高频耦合性能,且等效串联电阻较小。根据双膜态孔径分布理论,较大孔径的孔既可被水性电解液浸润也可被有机电解液浸润,较小孔径的孔则只能被水性电解液浸润。

The electric properties for high specific surface area activated carbons prepared from coal under optimum conditions were evaluated as electrodes in aqueous and organic electrolytes. The corresponding charge/discharge curves at constant current, equivalent series resistance（ESR） and leakage current were determined. The results show that the coal-based activated carbons has excellent power storage performance, stable electrochemical performance and impulse properties. The specific capacitance values in aqueous and organic electrolytes are 204F/g and 158F/g. Excel- lent high frequency coupling performance and small ESR are exhibited in aqueous electrolyte. This can be explained by a bimodal pore size distributio^large pores accessible to both electrolytes and small pores accessible only to the aqueous electrolyte.