Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (3): 485-491.doi: 10.3866/PKU.WHXB201401131

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Effects of Separator on the Electrochemical Performance of Electrical Double-Layer Capacitor and Hybrid Battery-Supercapacitor

SUN Xian-Zhong, ZHANG Xiong, HUANG Bo, MA Yan-Wei   

  1. Key Laboratory of Applied Superconductivity, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, P. R. China
  • Received:2013-10-21 Revised:2014-01-11 Published:2014-02-27
  • Contact: MA Yan-Wei E-mail:ywma@mail.iee.ac.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51025726, 51307167).

Abstract:

Separators are important components in electrochemical energy storage devices such as electrical double layer capacitors (EDLCs) and hybrid battery-supercapacitors. We prepared activated carbon-based EDLCs using an electrolyte of 1 mol ·L-1 tetraethyl ammonium tetrafluoroborate (Et4NBF4) in propylene carbonate (PC), and (LiNi0.5Co0.2Mn0.3O2+activated carbon)/graphite hybrid battery-supercapacitors using a 1 mol·L-1 lithium hexafluorophate (LiPF6) Li-ion electrolyte. The physicochemical properties and effect of various separators on the electrochemical properties of the EDLC and hybrid battery-supercapacitor were studied. The four separators were nonwoven polypropylene (PP) mat, porous PP membrane, Al2O3-coated PP membrane, and cellulose paper. The surface morphology, differential scanning calorimetry, electrolyte uptake, and apparent contact angle were investigated. The electrochemical characterizations of coin cells indicated that the EDLC with cellulose separator had the highest specific capacitance and rate capability. Differences in the selfdischarge of the four cells were not obvious. The specific capacities of the hybrid battery-supercapacitors with PP membrane and nonwoven PP mat separators were approximately 20% higher than the others. The capacitor with the cellulose paper separator had the highest self-discharge rate.

Key words: Electrical double-layer capacitor, Hybrid battery-supercapacitor, Electrolyte uptake, Apparent contact angle, Self-discharge

MSC2000: 

  • O646