Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (02): 479-485.doi: 10.3866/PKU.WHXB20110221

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Influence of Electrolyte Concentration and Temperature on the Capacitance of Activated Carbon

TIAN Ying1,2, YAN Jing-Wang1, XUE Rong1, YI Bao-Lian1   

  1. 1. Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning Province, P. R. China;
    2. College of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian 116028, Liaoning Province, P. R. China
  • Received:2010-08-24 Revised:2010-11-17 Published:2011-01-25
  • Contact: YAN Jing-Wang E-mail:yanjw@dicp.ac.cn
  • Supported by:

    The project was supported by the Important Directional Project of ‘The Research and Exploration of Supercapacitor Storage System for Electric Vehicle’ from Dalian Institute of Chemical Physics, Chinese Academy of Sciences, China.

Abstract:

The influences of electrolyte concentration and temperature on the capacitive behavior of activated carbon (AC) were investigated by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge/discharge measurements. The performance of a symmetric capacitor was characterized in 0.1, 0.5, 1.0, and 6.0 mol·L-1 KOH solution. We found that the high electrolyte concentration led to high capacitance, low internal resistance, and a narrow voltage window. The capacitance and internal resistance were found to be linearly dependent on the logarithm of KOH concentration. AC supercapacitor performance was investigated at 20, 40 and 80 °C, respectively. We found that elevated temperatures are favorable for an increase in capacitance and for a decrease in internal resistance. However, elevated temperatures increase the capacitance fading rate during long charge/discharge cycling tests.

Key words: Supercapacitor, Activated carbon, Electrolyte concentration, Temperature

MSC2000: 

  • O646