Microstructural Changes in Ni-YSZ Electrodes Operated in Fuel Cell and Electrolysis Modes: Effect of Gas Diffusion Limitations
Microstructural Changes in Ni-YSZ Electrodes Operated in Fuel Cell and Electrolysis Modes: Effect of Gas Diffusion Limitations
复制标题
燃料电池和电解模式下 Ni-YSZ 电极的微观结构变化：气体扩散限制的影响
DOI：
10.1149/11106.1907ecst
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Barnett, Scott A
中科院分区：
文献类型：
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作者：
Cox, Dalton;Barnett, Scott A
Ni-YSZ电极支撑对称电池分别在800℃、0、0.75、1.00和1.50 A/cm2条件下，在50% H2-50% H2O条件下工作1000 h，观察到高阳极过电位下阳极-电解质界面发生电化学断裂。随着时间的推移，在极化电池的阳极观察和量化Ni迁移；然而，阴极没有显示出与控制相比的迁移。气体扩散计算表明，蒸汽在阳极和阴极分别显著富集和耗尽，导致挥发性Ni (OH) x物质的形成或抑制，这被假设为Ni的运输途径。然而，气体通量计算表明，化学蒸发本身不太可能快到足以引起观察到的Ni损失。
Ni-YSZ electrode support symmetric cells were operated at 0, 0.75, 1.00, and 1.50 A/cm2 for 1000 h in 50% H2-50% H2O at 800 C. Electrochemical fracture at the anode-electrolyte interface is observed to occur under high anodic overpotential. Ni migration is observed and quantified over time at the anode of the polarized cells; however, the cathode shows no migration compared to control. Gas diffusion calculations show that steam is significantly enriched and depleted at the anode and cathode respectively, leading to the formation or suppression of volatile Ni (OH) x species, which have been hypothesized as a transport pathway for Ni. However, gas flux calculations show that chemical evaporation alone is unlikely to be fast enough to induce the Ni loss observed.