活性炭前处理对双电层电容器性能的影响

制备了沥青焦基活性炭双电层电容器用电极材料,将其分别经水洗、酸洗以及超音速气流粉碎处理。在1 mol/L(C2H5)4NBF4/碳酸丙烯酯电解液体系中进行电化学测试,对比评价了各活性炭前处理方法对电容器电化学性能的影响。结果表明,酸洗后活性炭电极比电容提高7%达到163 F/g,高功率放电性能明显改善,当电流密度由70 mA/g增加到1 A/g时,其电极比电容保持率为88%;活性炭进行超细粉碎后不利于电化学性能的提高。

Influence of activated carbon pretreatment on the electrochemical performance of the electric double layer capacitors

Pitch coke based activated carbon was prepared as electrode material for electric double layer capacitors(EDLC).The material was pre-treated by the methods of water and hydrochloric acid washing purification and jet pulverization respectively before prepared as electrodes of EDLCs.Electrochemical performances of the EDLCs in 1 mol/L(C2H5)4NBF4/ propylene carbonate(PC) electrolyte were characterized and compared by galvanostatic charge and discharge test and AC impedance spectrum analysis.The results show that the specific capacitance and the high power discharge performance of the hydrochloric acid washed activated carbon electrode are improved remarkably.The specific capacitance of the acid washed activated carbon electrode can reach 163 F/g,which is 7 % higher than that of the water washed activated carbon electrode,and as the current density increase from 70 mA/g to 1 A/g,the capacitance holding rate is 88 %.The pretreatment of jet pulverization cannot improve the electrochemical performance of the EDLC in PC electrolyte.