Why is the performance different between small- and large-scale SOFCs?
Why is the performance different between small- and large-scale SOFCs?
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为什么小型和大型SOFC的性能不同？
DOI：
10.1016/j.electacta.2023.141965
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发表时间：
2023
影响因子：
6.6
通讯作者：
Sato Kazuhisa
中科院分区：
文献类型：
--
作者：
Sumi Hirofumi;Shimada Hiroyuki;Yamaguchi Yuki;Nomura Katsuhiro;Sato Kazuhisa
直径为几厘米的小型平面固体氧化物燃料电池（SOFC）被称为“纽扣电池”或“硬币电池”，广泛用于基础研究。虽然大型电池的性能不如纽扣电池，但确切的原因尚不清楚。在本工作中，电化学阻抗谱（EIS）进行了不同的阴极面积在不同的燃料利用率下的纽扣电池，并进行弛豫时间的分布分析，以解卷积的EIS。纽扣电池的功率密度随着阴极直径的增加而降低。当纽扣电池的内电极区域和外电极区域之间的气体流动路径不同时，对于具有大阴极区域的电池，与在低频下的气体扩散过程相关联的极化电阻增加。与气体扩散过程相关的极化电阻也随着燃料利用率的增加而增加。作为考虑能斯特损耗的简单模拟的结果，对于尺寸为10 × 10 cm 2的大规模电池，在0.75 V下的功率密度估计为0.169 W/cm 2 atUf = 0.8，这小于阴极直径为6 mm的扣式电池的功率密度（0.730 W/cm 2 atUf = 0.04）。
Small-scale planar solid oxide fuel cells (SOFCs) with several centimeters in diameter called “button cells” or “coin cells” are widely used for fundamental research. Although the performance of large-scale cells is inferior to that of button cells, the precise reason is unclear. In the present work, electrochemical impedance spectroscopy (EIS) are performed for button cells with different cathode areas under different fuel utilization, and distribution of relaxation times analysis was conducted to deconvolute the EIS. The power density decreased with increasing cathode diameter for the button cells. The polarization resistances associated with the gas diffusion process at low frequencies increased for a cell with a large cathode area, when the gas flow path is different between the inner and outer electrode areas for the button cells. The polarization resistance related to the gas diffusion process also increases with increasing fuel utilization. As a result of simple simulation considering the Nernst loss, the power density at 0.75 V was estimated to be 0.169 W/cm2atUf= 0.8 for a large-scall cell with dimensions of 10 × 10 cm2, which is smaller than that for a button cell with a cathode diameter of 6 mm (0.730 W/cm2atUf= 0.04).