超级电容器活性炭电极循环伏安特性
2018-03-24张光宇徐芮赵鹏飞杨哲李闯吕胤霖陈玉娟朱大福杨昕瑞
张光宇 徐芮 赵鹏飞 杨哲 李闯 吕胤霖 陈玉娟 朱大福 杨昕瑞
摘要:针对活性炭电极超级电容器性能偏低的问题,依据双电层电容器工作原理,以活性炭、乙炔黑、质量分数为15%的聚四氟乙烯、异丙醇为原料,采用粉末压片技术,制备了活性炭质量分数分别为60%、65%、70%、75%和80%的超级电容器电极材料。通过扫描速率分别为5mV/s、10mV/s、20mV/s、50mV/s、100mV/s和200mV/s的循环伏安测试,分析了活性炭电极的比电容、比能量和比功率。结果表明,当活性炭质量分数为70%、扫描速率为5mV/s时,比电容为189.3F/g,比能量为26.3W·h/kg;当活性炭质量分数为70%、扫描速率为20mV/s时,比功率为916.6W/kg。确定了电极材料中活性炭的最优配比为70%,为基于活性炭电极的超级电容器制备提供了重要参考。
关键词:超级电容器;活性炭;循环伏安
DOI:10.15938/j.jhust.2018.01.026
中图分类号: O646
文献标志码: A
文章编号: 1007-2683(2018)01-0143-05
Abstract:For the problem of lower performance of supercapacitors based on activated carbon, according to a working principle of an electric double layer capacitor, activated carbon electrodes with mass fractions of 60%, 65%, 70%, 75% and 80% were prepared by a powder compression technology. Activated carbon, acetylene black, PTFE with the mass fraction of 15% and isopropanol were used as raw materials. The specific capacitance, the specific energy and the specific power of the activated carbon electrodes were analyzed through cyclic voltammetry tests with scanning rates at 5mV/s, 10mV/s, 20mV/s, 50mV/s, 100mV/s and 200mV/s. The results show that the specific capacitance is 189.3F/g and the specific energy is 26.3W·h/kg when the mass fraction of activated carbon is 70% and the scanning rate is 5mV/s. The specific power is 916.6W/kg when the mass fraction of activated carbon is 70% and the scanning rate is 20mV/s. This study confirms the optimal ratio of the mass fraction of activated carbon is 70%, providing an important reference for preparation of supercapacitors based on activated carbon electrodes.
Keywords:supercapacitor; activated carbon; cyclic voltammetry
0引言
超級电容器,又称为电化学电容器或超大容量电容器,是一种介于电池与普通电容之间兼备二者特点的新型储能器件[1-4]。其具有能量密度高、充放电速度快、循环寿命长、使用温度范围宽、免维护和经济环保等优点[5-8],在数字通信、电动汽车和高性能电源等领域具有广阔的应用前景。
目前,研究主要集中在Faraday赝电容器和双电层电容器两种类型[9-10]。前者采用过渡金属氧化物或导电聚合物做电极材料,在电极表面或体相中的二维或三维空间,电极活性物质进行欠电位沉积,发生高度可逆的化学吸附脱附或氧化还原反应,产生与电极充电电位有关的电容[11-12]。后者采用高比表面积炭电极材料,利用电极电解液界面扩散双电层来存储能量[13-15]。……
