Effects of pore structure and electrolyte on the capacitive characteristics of steam- and KOH-activated carbons for supercapacitors

被引:222
作者
Wu, FC
Tseng, RL
Hu, CC
Wang, CC
机构
[1] Natl United Univ, Dept Chem Engn, Miaoli 360, Taiwan
[2] Natl United Univ, Dept Safety Hlth & Environm Engn, Miaoli 360, Taiwan
[3] Natl Chung Cheng Univ, Dept Chem Engn, Chiayi 62107, Taiwan
关键词
activated carbon; steam activation; KOH activation; pore structure; surpercapacitor;
D O I
10.1016/j.jpowsour.2004.12.020
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Four kinds of activated carbons (denoted as ACs) with specific surface area of ca. 1050 m(2)g(-1) were fabricated from fir wood and pistachio shell by means of steam activation or chemical activation with KOH. Pore structures of ACs were characterized by a t-plot method based on N-2 adsorption isotherms. The amount of mesopores within KOH-activated carbons ranged from 9.2 to 15.3% while 33.3-49.5% of mesopores were obtained for the steam-activated carbons. The pore structure, surface functional groups, and raw materials of ACs, as well as pH and the supporting electrolyte were also found to be significant factors determining the capacitive characteristics of ACs. The excellent capacitive characteristics in both acidic and neutral media and the weak dependence of the specific capacitance on the scan rate of cyclic voltammetry (CV) for the ACs derived from the pistachio shell with steam activation (denoted as P-H2O-AC) revealed their promising potential in the application of supercapacitors. The ACs derived from fir wood with KOH activation (denoted as F-KOH-AC), on the other hand, showed the best capacitive performance in H2SO4 due to excellent reversibility and high specific capacitance (180 Fg(-1) measured at 10 mV s(-1)), which is obviously larger than 100 Fg(-1) (a typical value of activated carbons with specific surface areas equal to/above 1000 m(2)g(-1)). 0 2005 Elsevier B.V. All rights reserved.
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页码:302 / 309
页数:8
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