双电层电容器的电容特性分析

Analysis of capacitance of electric double layer capacitor

论述了EDLC的应用范围及对其性能的要求,分析了几种电容测试方法及其测试结果的差异,界定了电容的组成、物理意义及其相应的应用范围,把电容量分为计算电容、积分电容、表观电容和潜电容,计算电容倾向于微观结构及储电机理等理论研究,积分电容适用于后备电源型应用,表观电容则适于功率型的应用领域。研究了表观电容的特性及其影响因素,结果表明:微孔势垒的存在是表观电容的重要影响因素,也是产生伏安特性曲线上900mV后电流偏高现象的根本原因,同时造成了在微孔内形成双电层的滞后现象,形成了部分潜电容,提出了增加表观电容的措施,即降低电流密度或者提高充电电压。

The applied areas and their relevant performance of EDLC were discussed, and several capacitance value measures and their difference were analyzed. So the components of capacitance, and their physical meaning and corresponding applied areas were defined. The capacitance was disparted to calculating capacitance, integral capacitance, apparent capacitance and potential capacitance. Calculating capacitance is inclined to academic study about the microstructure and the mechanism of storage energy, integral capacitance is apt to the application of spare electrical source, and apparent capacitance is used to power supply. The characteristics and the effects of apparent capacitance were studied. The results show that the micropore potential barrier is a key effect of apparent capacitance, and is essential cause of the slight increase of current when the voltage is more than 900mV in cyclic vohammogram, and thus lead to the lag of forming electric double layer, which is potential capacitance. The measures, lowing current density or raising charge vohage, were provided to increase apparent capacitance