微结构,氧化层和电荷转移反应如何影响双层容量. 第1部分:阻抗光谱和循环电压测量以估计电化学活性表面积 (ECSA)
Maximilian Schalenbach1, Victor Selmert1,2, Ansgar Kretzschmar1
1Fundamental Electrochemistry (IEK-9), Institute of Energy and Climate Research, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425 Jülich, Germany. m.schalenbach@fz-juelich.de.
Physical chemistry chemical physics : PCCP
|May 2, 2024
概括
使用电容量估计电化学活性表面积 (ECSA) 是不可靠的,因为频率依赖的响应. 为了更准确的ECSA估计,建议在特征放松频率上使用标准化电容度量.
科学领域:
- 电化学 电化学 电化学
- 表面科学是一门学科.
背景情况:
- 电化学接口涉及通过电阻电容电流响应在双层 (DL) 中进行电荷重组.
- 电容量测量通常用于确定电化学活性表面积 (ECSA),但其可靠性尚未得到充分证实.
研究的目的:
- 在各种电极材料中批判性地评估电容量测量和ECSA之间的关系.
- 确定导致电容的频率依赖的因素,并提出ECSA估计的标准化方法.
主要方法:
- 使用了电化学阻抗光谱 (EIS) 和循环电压计 (CV).
- 从抛光电极 (Au,Ti,Ru,Pt,Ni,玻璃碳,石墨板) 和多孔碳羊毛收集数据.
- 分析重点关注来自DL响应,电荷转移和微观结构效应的频率依赖.
主要成果:
- 在各种电极中观察到测量容量的频率依赖性,其来源于DL响应,电荷转移和微观结构缓.
- 为ECSA估计,建议使用标准化的电容度指标,以标本特征的放松频率进行测量.
- 抛光的黄金和碳羊毛在1M酸中产生了电容度与表面积的比率,大约为3.7μF cm−2.
结论:
- 基于标准容量的ECSA估计因频率依赖性和微观结构效应而复杂化.
- 拟议的标准化电容度指标为ECSA确定提供了更可靠的方法.
- 开发了先进的等效电路模型来解释EIS和CV数据.
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