Investigation on the pseudocapacitive characteristics of the electrochemically modified graphite electrode in electrolytes with different pH

IMR OpenIR

	Investigation on the pseudocapacitive characteristics of the electrochemically modified graphite electrode in electrolytes with different pH
	Fan, Xinzhuang; Li, Yonggang; Wang, Shaoliang; Lu, Yonghong; Xu, Haibo; Liu, Jianguo; Yan, Chuanwei; xzfan@imr.ac.cn; xuwangri@163.com
	2015
发表期刊	ELECTROCHIMICA ACTA
ISSN	0013-4686
卷号	176 页码:70-76
摘要	The pseudocapacitive properties of an electrochemically modified graphite electrode (MGE) in electrolytes with different pH are investigated, and the transformation of the corresponding reaction mechanism and contribution of pseudocapacitance to the overall capacitance are analyzed in detail by cyclic voltammetry, electrochemical impedance spectroscopy and self-discharge tests. At low pH, the pseudocapacitance is attributed to the redox reaction among hydroxyl, carbonyl and carboxyl groups, which takes up nearly 61% of the overall capacitance. As the pH increases from 0 to 2, the carboxyl groups begin to ionize, the proportion of the redox reaction between carbonyl and carboxyl groups is decreased, and the contribution of pseudocapacitance to the overall capacitance decreases too. With the pH further increasing, the carboxyl groups are almost completely ionized and the redox reaction occurs only between hydroxyl and carbonyl groups, the contribution of pseudocapacitance drops to 33% and the double layer capacitance begins to play a dominate role. Despite of a lower specific capacitance for MGE in neutral solution, a broader potential window is obtained and the energy density would be increased nearly 1.33 times as large as that in acidic solution. The results indicate that the electrochemical system of MGE with the neutral electrolyte may be a promising candidate for a high energy density supercapacitor. (C) 2015 Elsevier Ltd. All rights reserved.
部门归属	[fan, xinzhuang ; wang, shaoliang ; liu, jianguo ; yan, chuanwei] chinese acad sci, inst met res, shenyang 110016, peoples r china ; [fan, xinzhuang ; lu, yonghong ; xu, haibo] ocean univ china, coll chem & chem engn, qingdao 266100, peoples r china ; [li, yonggang] qinghai univ, coll chem engn, xining 810016, peoples r china
关键词	Pseudocapacitance Ph Oxygen-containing Functional Groups Ionizability Potential Window
收录类别	sci
语种	英语
WOS记录号	WOS:000360918000011
引用统计	被引频次：9[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/74933
专题	中国科学院金属研究所
通讯作者	xzfan@imr.ac.cn; xuwangri@163.com
推荐引用方式 GB/T 7714	Fan, Xinzhuang,Li, Yonggang,Wang, Shaoliang,et al. Investigation on the pseudocapacitive characteristics of the electrochemically modified graphite electrode in electrolytes with different pH[J]. ELECTROCHIMICA ACTA,2015,176:70-76.
APA	Fan, Xinzhuang.,Li, Yonggang.,Wang, Shaoliang.,Lu, Yonghong.,Xu, Haibo.,...&xuwangri@163.com.(2015).Investigation on the pseudocapacitive characteristics of the electrochemically modified graphite electrode in electrolytes with different pH.ELECTROCHIMICA ACTA,176,70-76.
MLA	Fan, Xinzhuang,et al."Investigation on the pseudocapacitive characteristics of the electrochemically modified graphite electrode in electrolytes with different pH".ELECTROCHIMICA ACTA 176(2015):70-76.