Abstract
A process was proposed based on the combination of chemical and physical activation for the production of activated carbons used as the electrode material for electric double layer capacitor (EDLC). By material characterization and electrochemical methods, the influences of the activitation process on the specific surface area, pore structure and electrochemical properties of the activated carbons were investigated. The results show that specific surface area, the mesopore volume, and the specific capacitance increase with the increase of the mass ratio of KOH to char (m(KOH)/m(char)) and the activation time, respectively. When m(KOH)/m(char) is 4.0, the specific surface area and the mesopore volume reach the maximum values, i.e. 1 960 m2/g and 0.308 4 cm3/g, and the specific capacitance is 120.7 F/g synchronously. Compared with the chemical activation, the activated carbons prepared by chemical-physical activation show a larger mesopore volume, a higher ratio of mesopore and a larger specific capacitance.
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GAM Y J, TABERNA P L, SIMON P, FAUVARQUE J F. CHESNEAU M. Studies and characterizations of various activated carbons used for carbon/carbon supercapacitors [J]. Journal of Power Sources, 2001, 101(1): 109–116.
RUIZ V, BLANCO C, GRANDA M, SANTAMARIA R. Enhanced life-cycle supercapacitors by thermal treatment of mesophase-derived activated carbons [J]. Electrochimica Acta, 2008, 54(2): 305–310.
ZHAO Jia-chang, DAI Yang, XU Jing-li, CHEN Si-hao, XIE Jing-ying. Synthesis and electrochemical characterizaiton of mesoporous carbons prepared by chemical activation [J]. Journal of the Electrochemical Society, 2008, 155(7): A475–A480.
THOMAS E R, DEMISA H J, ZHU Z H, LU G Q. Mesoporous carbon electrode from waste coffee beans for high performance supercapacitors [J]. Electrochemistry Communications, 2008, 10(10):1594–1597.
TIAN Yong-ming, SONG Yan, TANG Zhi-hong, GUO Quan-gui, LIU Lang. Influence of high temperature treatment of porous carbon on the electrochemical performance in supercapacitor [J]. Journal of Power Sources, 2008, 184(2): 675–681.
XIA Kai-sheng, GAO Qiu-ming, JIANG Jin-hua, HU Juan. Hierarchical porous carbons with controlled micropores and mesopores for supercapacitor electrode materials [J]. Carbon, 2008, 46(13): 1718–1726.
BARBIERI O, HAHN M, KOTZ R. Capacitance limits of high surface area activated carbons for double layer capacitors [J]. Carbon, 2005, 43(6): 1303–1310.
LAI Yan-qing, LI Jing, SONG Hai-shen, ZHANG Zhi-an, LIU Ye-xiang. Preparation of activated carbons from mesophase pitch and their electrochemical properties [J]. Journal of Central South University of Technology, 2007, 14(5): 601–606.
YANG Jie, SHEN Zeng-min, HAO Zi-biao,. Preparation of highly microporous and mesoporous carbon from the mesophase pitch and its carbon foams with KOH [J]. Carbon, 2004, 42(2): 1872–1875.
KIERZEK K, FRACKOWIAK E, LOTA G, GRYGLEWICZ G, MACHNIKOWSKI J. Electrochemical capacitors based on highly porous carbons prepared by KOH activation [J]. Electrochimica Acta, 2004, 49(4): 515–523.
PRABAHARAN S R S, VIMALA R, ZAINAL Z. Nanostructure mesoporous carbon as electrodes for supercapacitors [J]. Journal of Power Sources, 2006, 161(1): 730–736.
KIM Y J, HORIE Y, MATSUZAWA Y, OZAKI S, ENDO M, DRESSELHAUS S M. Structure features necessary to obtain a high specific capacitance in electric double layer capacitor [J]. Carbon, 2004, 42(12/13): 2423–2432.
HUSSEIN M Z, TARMIZI R S H, ZAINAL Z, IBRAHIM R. Preparation and characterization of active carbons from oil palm shells [J]. Carbon, 1996, 34(11): 1447–1454.
LU W, CHUNG D D L. Mesoporous activated carbon filaments [J]. Carbon, 1997, 35(3): 427–437.
CARVALHO A P, CARDOSO B, PIRES J, CARBALHO M. Preparation of activated carbons from cork waste by chemical activation with KOH [J]. Carbon, 2003, 41(14): 2873–2884.
WU F C, TSENG R L, HU C C, WANG C C. The capacitive characteristics of activated carbons-Comparisons of the activation methods on the pore structure and effects of the pore structure and electrolyte on the capacitive performance [J]. Journal of Power Sources, 2006, 159(2): 1532–1542.
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Foundation item: Project(2007BAE12B01) supported by the National Key Technology Research and Development Program of China
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Zhang, Za., Cui, M., Lai, Yq. et al. Preparation and electrochemical characterization of activated carbons by chemical-physical activation. J. Cent. South Univ. Technol. 16, 91–95 (2009). https://doi.org/10.1007/s11771-009-0015-5
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DOI: https://doi.org/10.1007/s11771-009-0015-5