Unbiased Assessment of Electrochemical Windows: Minimizing Mass Transfer Effects on the Evaluation of Anodic and Cathodic Limits
Unbiased Assessment of Electrochemical Windows: Minimizing Mass Transfer Effects on the Evaluation of Anodic and Cathodic Limits
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DOI：
10.1149/2.068302jes
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发表时间：
2013-01-01
影响因子：
3.9
通讯作者：
Buehlmann, Philippe
中科院分区：
文献类型：
--
作者：
Olson, Eric J.;Buehlmann, Philippe
可用于电分析实验和电化学装置如超级电容器的最大电压受到电化学窗口的限制，在该电化学窗口内溶剂和电解质抵抗分解。在没有更好的定义的情况下，该窗口的极限通常被定义为实现任意值的电流密度的电势，这导致来自不同来源的值之间的不一致。我们提出了一个更有用的定义的电化学限制，较少依赖于实验参数，允许更有意义的比较数据从不同的调查。这里介绍的新方法将电化学极限定义为在低于和高于电化学电解质或溶剂分解的起始电位处的电流-电压关系的近似线性部分的截距，如通过线性扫描伏安法所确定的。为了证明这个定义的有用性，我们表明，它的使用几乎消除了浓度依赖性的电化学限制所造成的四丁基铵高氯酸盐的还原，它最大限度地减少了程度上的电化学限制，由于四烷基铵离子还原取决于烷基的长度。(C)2012年电化学学会。[DOI：10.1149/2.068302jes]版权所有。
The maximum voltage that can be used in electroanalytical experiments and electrochemical devices such as supercapacitors is limited by the electrochemical window within which the solvent and electrolyte resist decomposition. In the absence of a better definition, the limits of this window have been typically defined as the potentials at which a current density of an arbitrary value is achieved, which leads to inconsistencies between values from different sources. We propose a more useful definition of the electrochemical limits that depends less on experimental parameters, permitting more meaningful comparison of data from different investigators. The new method introduced here defines the electrochemical limit as the intercept of the approximately linear portions of the current-voltage relationship at potentials below and above the onset of electrochemical electrolyte or solvent decomposition, as determined by linear sweep voltammetry. To demonstrate the usefulness of this definition, we show that its use nearly eliminates the concentration dependence of the electrochemical limit caused by reduction of tetrabutylammonium perchlorate, and that it minimizes the extent to which the electrochemical limit due to tetraalkylammonium ion reduction depends on the length of the alkyl groups. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.068302jes] All rights reserved.