Proton and electron conductivity in hydrous ruthenium oxides evaluated by electrochemical impedance spectroscopy: The origin of large capacitance
Proton and electron conductivity in hydrous ruthenium oxides evaluated by electrochemical impedance spectroscopy: The origin of large capacitance
复制标题
DOI：
10.1021/jp044252o
复制
发表时间：
2005-04-21
影响因子：
3.3
通讯作者：
Takasu, Y
中科院分区：
文献类型：
--
作者：
Sugimoto, W;Iwata, H;Takasu, Y
采用电化学阻抗谱法研究了一系列水合钌氧化物RuO 2中心点xH（2）O（x = 0.5，0.3，0）和一种层状水合异油酸（H0.2RuO2.1中心点nH（2）O）的质子导电性和电子导电性。对于具有较高水含量的RuO 2中心点xH（2）O，在较低频率下观察到电容器响应频率，这被认为是由于膜内的电解质耗尽和/或利用具有高离子电阻的水合颗粒间微孔。阻抗数据分析表明，RuO 2中心点xH（2）O中的水含量对膜的电荷转移电阻没有显著影响，电容器频率响应主要由质子导电决定。层状H0.2RuO2.1中心点nH（2）O的电容器响应频率与RuO 2中心点0.5H（2）O相当。层状H0.2RuO2.1中心点nH（2）O在低频下的高比电容归因于可膨胀含水夹层的利用，这解释了离子导电性。目前的研究结果表明，水合区域（无论是粒子间或夹层），以允许可观的质子传导的高能量和高功率的电化学电容器的重要性。
Electrochemical impedance spectroscopy was conducted on a series of hydrous ruthenium oxides, RuO2 center dot xH(2)O, (x = 0.5, 0.3, 0) and a layered ruthenic acid hydrate (H0.2RuO2.1 center dot nH(2)O) in order to evaluate their protonic and electronic conduction. The capacitor response frequency was observed at lower frequency for RuO2 center dot xH(2)O with higher water content, which was suggested to be due to electrolyte exhaustion within the film and/or utilization of hydrated interparticle micropores that have high ionic resistance. Analysis of the impedance data indicated that the charge-transfer resistance through the film is not significantly affected by the water content in RuO2 center dot xH(2)O, and the capacitor frequency response is dominated by the protonic conduction. The capacitor response frequency of layered H0.2RuO2.1 center dot nH(2)O was comparable to RuO2 center dot 0.5H(2)O. The high specific capacitance at low frequency for layered H0.2RuO2.1 center dot nH(2)O is attributed to the utilization of the expandable hydrous interlayer, which accounts for the ionic conduction. The present results demonstrate the importance of hydrous regions (either interparticle or interlayer) to allow appreciable protonic conduction for high energy and high power electrochemical capacitors.