通过电导性放松反应在有孔电极中减少氧降低反应的表面积
Hairui Han1, Guanwei Guo1, Shaowei Zhang1
1CAS Key Laboratory of Materials for Energy Conversion, University of Science and Technology of China, No. 96 Jinzhai Road, Hefei, Anhui, 230026, P. R. China.
Chemistry (Weinheim an der Bergstrasse, Germany)
|August 29, 2024
概括
气体扩散显著影响固体氧化物燃料电池 (SOFC) 电极中的氧降解反应 (ORR). 为更快的气体运输优化电极结构对于提高ORR性能至关重要.
科学领域:
- 电化学 电化学 电化学
- 材料科学 材料科学 材料科学
- 化学工程是化学工程的重要组成部分.
背景情况:
- 在多孔电极中氧降解反应 (ORR) 的性能对于固体氧化物燃料电池 (SOFC) 至关重要.
- 在多孔介质中,气体扩散对ORR的影响需要进一步研究.
- 非热表面氧气交换问题与气体扩散限制有关.
研究的目的:
- 调查气体扩散对La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) 电极在ORR上的影响,其孔径和透性各不相同.
- 量化气体扩散对ORR可用的有效表面积的影响.
- 提出一种新的度量",减少表面积",以表示气体扩散效应在电极性能.
主要方法:
- 使用电导放松方法研究LSCF电极.
- 应用分布式特征时间 (DCT) 模型进行数据分析.
- 检测带有可控孔径,孔径和气体透性的电极.
主要成果:
- 在多孔电极中的ORR表现出三个特征时间:气体扩散,小孔表面交换和大孔表面交换.
- 气体扩散明显减缓了氧表面交换反应,降低了有效的化学氧表面交换系数.
- 定义了一个"减少表面积"指标,随气体透性而增加,以量化气体扩散效应.
结论:
- 气体扩散显著阻碍了多孔SOFC电极中的ORR动力学.
- 增强气体运输的电极工程对于提高SOFC性能至关重要.
- 使用ALS模型计算电极极化阻抗时,建议将"减少表面积"度量作为比特定表面积更准确的参数.
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