双电层电容器中单/双面涂覆电极的电化学性能比较

以KOH为活化剂,采用微波加热石油焦一步法制备了微孔活性炭。采用循环伏安和恒流放电法研究了双电层电容器中单面和双面涂覆的活性炭电极电化学性能。活性炭的亚甲基蓝吸附值为247.8mg·g–1,N2吸/脱附结果表明,活性炭比表面积为1037m2·g–1,微孔孔容为0.54m3·g–1。结果表明,1000次循环后,双面涂覆电极的比容、比容保持率和两电极电容器的能量密度保持率分别为227.3F·g–1、96.6%和97.4%均高于单面涂覆电极;而双面涂覆电极的内阻仅为0.42Ω,小于单面涂覆电极的内阻。

Comparison on electrochemical performance of single-face and double-face covered electrodes for electric double layer capacitor

One-step synthesis of microporous activated carbon (AC) was introduced by microwave heating petroleum coke with KOH as activation agent. Electrochemical performance of single-face and double-face covered AC electrodes for electric double layer capacitor were studied by cyclic voltammetry and galvanostatic charge-discharge. The results show that the adsorption capacity of AC is 247.8 mg·g~(-1) for methylene blue. The results of N_2 adsorption-desorption show that the specific surface area and the micropore volume of AC reaches 1 037 m~2·g~(-1) and 0.54 m~3·g~(-1), respectively. The specific capacitance and the maintenance of specific capacitance as well as energy density of double-face covered AC electrodes are 227.3 F·g~(-1), 96.6% and 97.4%, respectively, which are bigger than those of single-face covered AC electrodes. On the contrary, the equivalent series resistance of the former is only 0.42 Ω, which is smaller than that of single-face covered AC electrodes.