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过程工程学报 ›› 2019, Vol. 19 ›› Issue (6): 1242-1249.DOI: 10.12034/j.issn.1009-606X.219116

• 环境与能源 • 上一篇    下一篇

有机添加剂对超级电容器中水系电解液理化性能的影响

刘桐桐1,2， 王 凯1,2， 陈永修1,2， 韩永生1,2*   

  1. 1. 中国科学院过程工程研究所多相复杂系统国家重点实验室，北京 100190 2. 中国科学院大学化工学院，北京 100049
  • 收稿日期:2019-01-21 修回日期:2019-04-03 出版日期:2019-12-22 发布日期:2019-12-22
  • 通讯作者: 韩永生 yshan@ipe.ac.cn
  • 基金资助:
    高芳烃高含氮重油催化转化反应基础研究;高芳烃高含氮重油催化转化反应基础研究;石油联合基金

Effect of organic additives on the electrochemical performance of aqueous electrolyte in supercapacitors

Tongtong LIU1,2, Kai WANG1,2, Yongxiu CHEN1,2, Yongsheng HAN1,2*   

  1. 1. State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China 2. School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2019-01-21 Revised:2019-04-03 Online:2019-12-22 Published:2019-12-22

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摘要： 以6 mol/L KOH水溶液为电解液，高比表面积的活性炭为活性物质，研究了有机添加剂对体系润湿性、电导率、工作电压窗口及阻抗的影响，测试了超级电容器的电化学性能。结果表明，适量添加有机添加剂可明显抑制体系的极化现象，提高超级电容器的工作电压窗口。添加10vol%异丙醇时，电极材料和电解液间的润湿性大幅提高，比电容从79.3 F/g提高至113.2 F/g。添加20vol%异丙醇时，超级电容器的能量密度达19.4 Wh/kg，体系的电荷转移电阻明显降低，在10 A/g电流密度下的比电容比0.5 A/g时下降13.9%，而不加添加剂时下降30.3%。添加30vol%异丙醇时，电解液电导率迅速下降，比电容降低，电导率是影响比电容的关键因素。

关键词: 超级电容器, 润湿性, 电导率, 工作电压窗口, 电化学性能

Abstract: The components of electrolytes play an important role in determining the properties of supercapacitors. Different electrolytes have their superiority and disadvantages. Aqueous electrolyte is one of the electrolytes used in supercapacitors, but it is limited in industrialization because of its narrow voltage window and low energy density. The addition of organic solvents could enhance the performance of supercapacitors, which has gained more and more attention in this research direction. In this work, 6 mol/L KOH solution was used as the electrolyte, and the activated carbon with high specific surface area was used as electrode material. The effects of organic additives on the electrochemical performance and energy density of supercapacitors in aqueous electrolytes were investigated. The electrochemical properties of the supercapacitor were researched after adding different kinds of organic additives in the aqueous electrolyte. The results showed that the polarization phenomenon of the system can be significantly suppressed due to the addition of appropriate organic additives, the operating voltage window and energy density of the supercapacitor were improved. After 10vol% isopropanol was added to the aqueous electrolyte, the wettability between the electrode material and the electrolyte was greatly improved, and the specific capacity increased from 79.3 F/g to 113.2 F/g. Adding 20vol% isopropanol, the working voltage window of the system increased from ?0.8~0 V to ?0.8~0.5 V, the energy density of the supercapacitor reached 19.4 Wh/kg, the charge transfer resistance of the system was significantly reduced, the specific capacity decreased by 13.9% at 10 A/g than it was at 0.5 A/g while the specific capacity decreased by 30.3% without additives. However, when 30vol% isopropanol was added, since the ion transfer at the viscous electrolyte was limited, the conductivity was greatly lowered, resulting in rapid decay of the specific capacitance.

Key words: Supercapacitors, Wettability, Conductivity, Voltage window, Electrochemical performance