電容特性的影響
(中南大學 冶金科學與工程學院，長沙 410083)
摘 要: 以煤焦油瀝青為原料，在不同溫度下調制得到碳質微晶結構的中間相瀝青，采用化學活化法制得超級電容器用高比表面積活性炭。以制備的活性炭作電極材料組裝模擬電容器，6 mol/L KOH溶液為電解液，考察了中間相瀝青的調制溫度對活性炭結構和電容行為的影響。結果表明：隨著調制溫度的提高，活性炭比表面積先增加后減小，在
關鍵字: 超級電容器；中間相瀝青；活性炭；化學活化
on structure and electrochemical performance of activated carbons
ZHANG Zhi-an, LU Hai
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:Using coal-tar pitch as raw material, the mesophase pitches with carbonaceous crystallites were produced at different temperatures, and the ultra-high surface area activated carbons for supercapacitors were prepared by chemical activation. Coin type cells using the prepared activated carbons as electrode materials were assembled, and 6 mol/L KOH solution was selected as the electrolyte. The effects of modification process of the mesophase pitches on the structures and the electrochemical behaviors of activated carbons were investigated. The results indicate that the specific surface area of activated carbons increases while then decreases with increasing temperature, and the surface area of activated carbon modificated at 450 ℃ is 3 250 m2/g. The micropore sizes are ranged from 1nm to 4 nm, and the unformed structure modificated at 350 ℃ is beneficial to pore-widening, so the activated carbons exhibits higher mesopore volume. When the temperature increases, the mesopore volume decreases. The capacitance of the activated carbon increases while then decreases with increasing temperature, and the maximum specific capacitance is 215 F/g, which is acquired from the carbon modificated at 450 ℃.
Key words: supercapacitor; mesophase pitch; activated carbon; chemical activation
