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超级电容器用新型微晶炭的结构及其电容性能
Structures and Capacitance Characteristics of the Novel Crystallite Carbon for Supercapacitor
【摘要】 以热处理后的煤沥青焦为原料,采用KOH活化法制备了具有较小比表面积(<200m2/g)的系列微晶炭。采用N2吸附、X射线衍射(XRD)和X射线光电子能谱(XPS)等手段表征了微晶炭的孔结构、微晶结构以及表面化学性质,研究了微晶炭作为超级电容器电极材料在1 mol/L的四乙基四氟化硼酸铵盐/碳酸丙烯酯电解液体系中的电容性能。结果表明:制得的微晶炭具有大量类石墨微晶和较高的石墨化度,d002(晶面层间距)为0.356~0.666 nm,表面含碳量大于95%;活化6 h后,在4.0 V下微晶炭的质量比电容高达139 F/g。微晶炭的储电行为包括插层电容和双电层电容两部分,其中电活化所造成的插层电容是决定微晶炭最终比电容的主要因素,插层电容主要由电极材料的石墨化度决定。
【Abstract】 Crystallite carbons(CCs) with low BET specific surface area(<200 m2/g) have been prepared by KOH activation from pre-heated coal pitch based cokes.The pore structure,crystallite structure and surface chemistry of CCs were investigated by N2 adsorption,X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS),respectively.The capacitance performance of CCs as electrode materials for supercapacitors in 1 mol/L tetraethylammonium tetra-fluoroborate/propylene carbonate(Et4NBF4/PC) electrolyte was evaluated.Results reveal that CCs have a large amount of graphite-like crystallites and high graphitization degree.The value of d002 is in the range of 0.356 to 0.666 nm and the surface carbon contents are above 95%.When activating time is 6 h,the obtained CCs shows maximum mass capacitance of 139 F/g charging at 4.0 V.The energy storage behaviors are mainly composed of intercalation capacitance and electrochemical double-layer capacitance.The intercalation capacitance initiated by "electrical activation" is the main part of the whole capacitance and the value is determined by graphitization degree of the electrode material.
【Key words】 crystallite carbon; graphite-like crystallite; electrical activation; intercalation;
- 【文献出处】 华东理工大学学报(自然科学版) ,Journal of East China University of Science and Technology(Natural Science Edition) , 编辑部邮箱 ,2009年06期
- 【分类号】TM53
- 【被引频次】8
- 【下载频次】389