Silicon oxycarbide-derived carbons from a polyphenylsilsequioxane precursor for supercapacitor applications

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• 作者：Andreas Meier ; Manuel Weinberger ; Katja Pinkert ; Martin Oschatz ; Silvia Paasch ; Lars Giebeler ; Holger Althues ; Eike Brunner ; J眉rgen Eckert ; Stefan Kaskel
• 关键词：Xerogel ; Silicon oxycarbide-derived carbon ; Supercapacitor ; Organic electrolyte
• 刊名：Microporous and Mesoporous Materials
• 出版年：April, 2014
• 年：2014
• 卷：188
• 期：Complete
• 页码：140-148
• 全文大小：2244 K

文摘

In this study, we report on the preparation of new silicon oxycarbide-derived carbons (SiOCDC) obtained by pyrolysis and chlorination of a polyphenylsilsesquioxane pre-ceramic precursor. Wet-chemical conversion of phenyltrimethoxysilane (PhTMS) to the organosilica material was conducted using a two-step acid/base sol-gel process in aqueous medium. The resulting material was subsequently pyrolysed at 700, 1000 and 1300 掳C to obtain a non-porous silicon oxycarbide ceramic. Chlorination at 700 and 1000 掳C led to carbons having large surface areas exceeding 2000 m² g^鈭? as well as large micro-/mesopore volumes up to 1.4 cm³ g^鈭?. The temperature of the thermal treatment significantly influences the carbon and final pore structure. Pyrolysis at 700 掳C and subsequent chlorination at 700 掳C led to a mainly microporous material, whereas pyrolysis at 1300 掳C and subsequent chlorination at 1000 掳C generated a hierarchically porous SiOCDC with micro- and mesopores, respectively. All SiOCDC materials were prepared as supercapacitor electrodes using an aqueous slurry containing polytetrafluoroethylene (PTFE) and sodium carboxymethyl cellulose (CMC) as binder. With an organic electrolyte (1 M TEABF₄ in acetonitrile) capacitances of up to 110 F g^鈭? and good long term stabilities could be observed.