The fractal nature of the three-phase boundary: A heuristic approach to the degradation of nanostructured solid oxide fuel cell anodes
The fractal nature of the three-phase boundary: A heuristic approach to the degradation of nanostructured solid oxide fuel cell anodes
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DOI：
10.1016/j.nanoen.2017.06.028
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发表时间：
2017-08-01
期刊：
影响因子：
17.6
通讯作者：
Brandon, N. P.
中科院分区：
文献类型：
--
作者：
Bertei, A.;Ruiz-Trejo, E.;Brandon, N. P.
用于固体氧化物燃料电池的镍/氧化锆基纳米结构电极即使在中间温度下也具有差的稳定性。本研究结合三维断层扫描，电化学阻抗谱（EIS）和机械建模，量化的电化学和微观结构的纳米结构电极的退化。第一次，电化学降解的纳米结构电极是根据三相边界（TPB）的分形性质进行量化。使用这一假设，发现建模与电化学响应之间具有良好的匹配。微观结构和电化学性能退化的根源可以在TPB的初始分形粗糙度中找到，其长度尺度是最先进的断层扫描无法检测到的。30纳米分辨率。这另外意味着氢电氧化发生在距离几何TPB线4 nm内，揭示了当处理纳米颗粒时，电化学反应区不能再被视为一维线。
Nickel/zirconia-based nanostructured electrodes for solid oxide fuel cells suffer from poor stability even at intermediate temperature. This study quantifies the electrochemical and microstructural degradation of nanostructured electrodes by combining 3D tomography, electrochemical impedance spectroscopy (EIS) and mechanistic modeling. For the first time, the electrochemical degradation of nanostructured electrodes is quantified according to the fractal nature of the three-phase boundary (TPB). Using this hypothesis an excellent match between modeling and the electrochemical response is found. The origin of the degradation in microstructure and electrochemical performance can be found in the initial fractal roughness of the TPB at a length scale not detectable with state-of-the-art tomography at 30 nm resolution. This additionally implies that the hydrogen electro-oxidation takes place within 4 nm from the geometric TPB line, revealing that the electrochemical reaction zone cannot be regarded anymore as a one-dimensional line when dealing with nanoparticles.