Electrochemical Properties of Asymmetric Supercapacitors in Potassium Hydroxide Electrolyte

Abstract:

Three kinds of activated carbons were prepared from Taixi anthracite by NaOH activation. As-obtained activated carbons were adopted as electrode materials to construct asymmetric and symmetric supercapacitors. The electrochemical properties of as-constructed supercapacitors in aqueous electrolyte (3.0M KOH) were investigated. Results show that the asymmetric supercapacitor assembled with activated carbon of a higher specific surface area (SBET) as the positive electrode exhibits better ion diffusion behavior and higher cell gravimetric specific capacitance (Cg). This is different from the case in non-aqueous system, mainly because pseudo-capacitance rather than double-layer capacitance has a more important effect on Cg in the aqueous electrolyte. Namely, the wettability and pseudo-capacitance of activated carbons decrease with increasing mass ratio of NaOH to anthracite, which is more prominent for activated carbons used as negative electrode materials.

• Periodical: Advanced Materials Research (Volume 459)
• Pages: 488-491
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.459.488
• Online since: January 2012
• Authors: Guang Xu Huang, Bao Lin Xing, Chuan Xiang Zhang, Lun Jian Chen
• Keywords: Activated Carbon, Aqueous Electrolyte, Asymmetric Supercapacitor, Electrochemical Property

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