Fang Baizeng, Binder Leo
Institute for Chemical Technology of Inorganic Materials, Graz University of Technology, Stremayrgasse 16/III, A-8010 Graz, Austria.
J Phys Chem B. 2006 Apr 20;110(15):7877-82. doi: 10.1021/jp060110d.
Porous materials, developed by grafting functional groups through chemical surface modification with a surfactant, represent an innovative concept in energy storage. This work reports, in detail, the first practical realization of a novel carbon electrode based on grafting of vinyltrimethoxysilane (vtmos) functional group for energy storage in electric double layer capacitor (EDLC). Surface modification with surfactant vtmos enhances the hydrophobisation of activated carbon and the affinity toward propylene carbonate (PC) solvent, which improves the wettability of activated carbon in the electrolyte solution based on PC solvent, resulting in not only a lower resistance to the transport of electrolyte ions within micropores of activated carbon but also more usable surface area for the formation of electric double layer, and accordingly, higher specific capacitance, energy density, and power capability available from the capacitor based on modified carbon. Especially, the effects from surface modification become superior at higher discharge rate, at which much better EDLC performance (i.e., much higher energy density and power capability) has been achieved by the modified carbon, suggesting that the modified carbon is a novel and very promising electrode material of EDLC for large current applications where both high energy density and power capability are required.
通过用表面活性剂进行化学表面改性接枝官能团而开发的多孔材料，代表了储能领域的一个创新概念。这项工作详细报道了基于接枝乙烯基三甲氧基硅烷（vtmos）官能团的新型碳电极在双电层电容器（EDLC）中储能的首次实际实现。用表面活性剂vtmos进行表面改性增强了活性炭的疏水化以及对碳酸丙烯酯（PC）溶剂的亲和力，这改善了活性炭在基于PC溶剂的电解质溶液中的润湿性，不仅降低了电解质离子在活性炭微孔内传输的阻力，还增加了形成双电层的可用表面积，因此，基于改性碳的电容器具有更高的比电容、能量密度和功率性能。特别是，表面改性的效果在较高放电速率下更为显著，在该速率下，改性碳实现了更好的EDLC性能（即更高的能量密度和功率性能），这表明改性碳是一种新型且非常有前景的EDLC电极材料，适用于需要高能量密度和功率性能的大电流应用。
