Faradic resistance of the electrode/electrolyte interface
Faradic resistance of the electrode/electrolyte interface
复制标题
电极/电解质界面的法拉第电阻
DOI：
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发表时间：
1992
影响因子：
3.2
通讯作者：
L. Ogborn
中科院分区：
文献类型：
--
作者：
S. Mayer;L. Geddes;J. Bourland;L. Ogborn
使用一种新方法来测量单个电极/电解质界面的直流（法拉第）电阻。该方法采用恒流脉冲和电势传感电极。通过选择足够长的脉冲持续时间，测试电极和电势感测电极之间的电压表现出三相响应。在稳态阶段，测量的电压等于流过电极的电流法拉第电阻和测试电极与电势传感电极之间电解质的电阻。通过用高频正弦交流电测量后一个电阻，计算电解质中的电压降，并将其从测试电极和电势感测电极之间测量的电压中减去，从而计算法拉第电阻。通过绘制法拉第电阻与电流密度的倒数并将数据点拟合到三阶多项式，可以确定零电流密度（法拉第）电阻。该技术用于测定不锈钢、铂、铂铱和铑电极（0·1 cm2）在 25°C 0·9% NaCl 中的法拉第电阻。铂的零电流法拉第电阻最低 (30·3 kΩ)，铂铱合金稍高 (47·6kΩ)，铑合金高得多 (111 kΩ)，316 型不锈钢最高 (345 kΩ)。在所有情况下，法拉第电阻随着电流密度的增加而急剧下降。
A new method is used to measure the direct-current (Faradic) resistance of a single electrode/electrolyte interface. The method employs a constant-current pulse and a potential-sensing electrode. By choosing a sufficiently long pulse duration, the voltage between the test and potential-sensing electrode exhibits a three-phase response. In the steady-state phase, the voltage measured is equal to the current flowing through the electrode Faradic resistance and the resistance of the electrolyte between the test and potential-sensing electrode. By measuring this latter resistance with a high-frequency sinusoidal alternating current, the voltage drop in the electrolyte is calculated and subtracted from the voltage measured between the test and potential-sensing electrode, thereby allowing calculation of the Faradic resistance. By plotting the reciprocal of the Faradic resistance against current density and fitting the data points to a third-order polynomial, it is possible to determine the zero-current density (Faradic) resistance. This technique was used to determine the Faradic resistance of electrodes (0·1 cm2) of stainless-steel, platinum, platinum-iridium and rhodium in 0·9 per cent NaCl at 25°C. The zero current Faradic resistance is lowest for platinum (30·3 kΩ), slightly higher for platinum-iridium (47·6kΩ), much higher for rhodium (111 kΩ) and highest for type 316 stainless-steel (345 kΩ). In all cases, the Faradic resistance decreases dramatically with increasing current density.