A multiscale model has been used to optimize the microstructure of a classical hydrogen electrode made of nickel and yttria-stabilized zirconia (Ni-8YSZ). For this purpose, a 3D reconstruction of a reference electrode has been obtained by X-ray nano-holotomography. Then, a large dataset of synthetic microstructures has been generated around this reference with the truncated Gaussian random field method, varying the ratio Ni/8YSZ and the Ni particle size. All the synthetic microstructures have been introduced in a multiscale modeling approach to analyze the impact of the microstructure on the electrode and cell responses. The local electrode polarization resistance in the hydrogen electrode, as well as the complete cell impedance spectra, have been computed for the different microstructures. A significant performance improvement was found when decreasing the Ni particle size distribution. Moreover, an optimum has been identified in terms of electrode composition allowing the minimization of the cell polarization resistance. The same methodology has been also applied to assess the relevance of graded electrodes. All these results allow a better understanding of the precise role of microstructure on cell performances and provide useful guidance for cell manufacturing.

中文翻译：

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固体氧化物电池氢电极的数值微观结构优化

多尺度模型已用于优化由镍和氧化钇稳定的氧化锆 (Ni-8YSZ) 制成的经典氢电极的微观结构。为此，通过 X 射线纳米全息断层扫描获得了参考电极的 3D 重建。然后，使用截断高斯随机场方法，改变 Ni/8YSZ 比率和 Ni 颗粒尺寸，围绕该参考生成了一个大型合成微观结构数据集。所有合成微观结构均已引入多尺度建模方法中，以分析微观结构对电极和细胞响应的影响。已经针对不同的微观结构计算了氢电极中的局部电极极化电阻以及完整的电池阻抗谱。当减小镍颗粒尺寸分布时，发现显着的性能改进。此外，在电极组成方面已经确定了最佳方案，可以使电池极化电阻最小化。同样的方法也被用于评估分级电极的相关性。所有这些结果使我们能够更好地了解微观结构对电池性能的精确作用，并为电池制造提供有用的指导。