Preparation and electrochemical properties of pitch-based activated carbon aerogels

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• 作者：Xianhua Zeng ; Dingcai Wu ; Ruowen Fu ; Huajie Lai ; Junjia Fu
• 关键词：Electrochemical capacitor ; Pitch-based carbon aerogels ; Activation ; Porous structure ; Specific capacitance
• 刊名：Electrochimica Acta
• 出版年：2008
• 出版时间：20 July 2008
• 年：2008
• 卷：53
• 期：18
• 页码：5711-5715
• 全文大小：455 K

文摘

The porous structure of pitch-based carbon aerogels (P-CAs) can be modified by KOH activation. It is found that decreasing the carbonization temperature of precursor CAs and increasing the mass ratio of KOH to CAs help to the formation of 0.7 nm-sized micropores and 2.7 nm-sized mesopores, respectively. The origin and the pore size of micropores play an important role in controlling electrochemical properties. The carbonization-forming micropores have stronger energy storage efficiency than activation-forming micropores, and only those with diameter below 1 nm (Microp < 1 nm) are the crucial place to storage energy. Due to the substantive increase of the number of the Microp < 1 nm, the highest specific capacitance of the as-prepared activated samples can reach 187.2 F g⁻¹ at 5 mA cm⁻², 1.8 times as large as that of their precursor CAs. Furthermore, this capacitance is still up to 173.3 F g⁻¹ when increasing the current density to 50 mA cm⁻², indicating that the activated samples have a high-rate charge–discharge performance.