Among the diverse approaches for improving the electrode performance of solid oxide fuel cells operating at intermediate temperatures, the use of nanofiber-based electrodes has provided large improvement owing to their large specific surface area, continuous conduction pathway, and highly porous structure. However, the low thermal stability at increased temperature often limits the process compatibility and sustainability during operation. In this study, we fabricated nanofiber-based electrodes with a high porosity and hollow shape using one-step electrospinning with a hydrogel polymer, which exhibited largely improved performance and excellent thermal stability. A porous-nanofiber-based cell exhibits a polarization resistance of 0.021 Ωcm2 and maximum power density of 1.71 W/cm2 at 650 °C, which is an improvement of 34.3% and 14.7% compared to that of a solid-nanofiber-based cell, respectively. Comprehensive analyses of the microstructures and chemistry indicate that the performance increase is mainly attributable to the enhanced surface oxygen exchange reactions owing to the extended reaction sites with lower energy barriers by the high porosity and enriched oxygen vacancies in the nanofibers.

中文翻译：

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用于固体氧化物燃料电池电极的多孔中空纳米纤维

在提高在中等温度下运行的固体氧化物燃料电池的电极性能的多种方法中，纳米纤维基电极的使用提供了很大的改进，因为它们具有大的比表面积、连续的传导通路和高度多孔的结构。然而，在升高的温度下的低热稳定性通常限制了操作过程中的工艺兼容性和可持续性。在这项研究中，我们使用水凝胶聚合物一步静电纺丝制造了具有高孔隙率和中空形状的纳米纤维基电极，该电极表现出大大提高的性能和出色的热稳定性。基于多孔纳米纤维的电池在 650°C 下的极化电阻为 0.021 Ωcm2，最大功率密度为 1.71 W/cm2，分别提高了 34.3% 和 14%。与基于固体纳米纤维的电池相比，分别为 7%。微观结构和化学的综合分析表明，性能提高主要归因于纳米纤维中的高孔隙率和富氧空位导致的扩展反应位点和较低的能量势垒，从而增强了表面氧交换反应。