High Power Density Electric Double Layer Capacitor with Improved Activated Carbon

✍ Scribed by Yang Hui; Jiang Hui-Jun; Lu Tian-Hong

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 363 KB
• Volume: 21
• Category: Article
• ISSN: 0256-7660
• DOI: 10.1002/cjoc.20030210202

✦ Synopsis

Abstract

The improvement on commercial activated carbon (AC) through the reactivation under steam in the presence of NiCl~2~ catalyst leads to the increases of both energy and power densities of electric double layer (dl) capacitors. When AC was treated at 875 °C for 1 h, its discharge specific capacitance increases up to 53.67 F· g^−1^, an increase of about 25% compared to the as‐received AC. Moreover, a significant increase in high rate capability of electric dl capacitor was found after the improvements. Surprisingly, both the treated and untreated AC samples showed similar specific surface area and pore size distribution, but some changes in the surface groups and their concentrations after reactivation were verified by X‐photoelectron spectra. Thus, it is reasonable to conclude that the decrease in the surface concentration of the carbonyl‐containing species for the improved AC results in an increase of accessibility of the pores to the organic electrolyte ion, causing the enhancements of both the specific capacitance and high rate capability.