高比表面积电极有机双电层电容器性能

Organic double-layer capacitor with high surface area electrodes

采用高比表面积椰壳基活性炭作电极材料,分别以1mol/L (Et)4NBF4/PC、1mol/L LiPF6/(PC+DMC+EMC)、1mol/L LiPF6/(EC+DMC+EMC)和1mol/L LiClO4/PC作为电解液,组装成有机体系双电层电容器。采用恒流充放电法、循环伏安法和交流阻抗法进行测试,考察采用同种电极材料情况下,各种有机电容器的电化学性能,在不同充电电压下均以1mol/L LiClO4/PC为电解液时得到最高比电容值(2.5V时高达123.5F/g),1mol/L(Et)4NBF4/PC的比电容值也比较理想(2.5V时为104F/g),且其内阻最小,功率特性最佳。综合分析得知,以1mol/L LiClO4/PC为电解液的双电层电容器综合性能最佳,且此电解液价格较1mol/L (Et)4NBF4/PC低廉。

A high surface area activated carbon （2516 m^2/g） was chosen for electric double layer capacitors with 1 mol/L （Et）4NBF4/PC, 1 mol/L LiPF6/（PC＋DMC＋EMC）, 1 mol/L LiPF6/（EC＋DMC＋EMC） and 1 mol/L LiCIO4/PC as electrolytes. The characteristic of capacitors was investigated by cyclic voltammetry, AC impadence and a constant current charge-discharge test. The results show that the specific capacitance is the greatest in different potentials when 1 mol/L LiClO4/PC is used as the electrolyte. The specific capacitance was as high as 123.5 F/g at 2.5 V. In addition, the specific capacitance with 1 mol/L （Et）4NBF4/PC was also ideal （104 F/g in 2.5 V） with the least impedance and the best power characterization. It was concluded that using 1 mol/L LiClO4/PC as electrolyte could decrease the cost of capacitors because of its lower price.