Chemically-induced stresses in gadolinium-doped ceria solid oxide fuel cell electrolytes
Chemically-induced stresses in gadolinium-doped ceria solid oxide fuel cell electrolytes
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DOI：
10.1016/s0167-2738(96)00588-7
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发表时间：
1997-03-01
影响因子：
3.2
通讯作者：
Atkinson, A
中科院分区：
文献类型：
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作者：
Atkinson, A
掺杂钆的氧化铈是一种用于在500-800 ℃温度范围内工作的固体氧化物燃料电池（SOFC）的有吸引力的电解质材料。在SOFC阳极的低氧活性条件下，二氧化铈被部分还原并且其晶格参数增加，导致电解质中产生应力。这些应力已被计算为一系列不同的参数（Gd掺杂水平，温度，氧活性和电池电流）和不同的几何配置的初始平面电解质膜（自支撑或支持在多孔基板上）。计算结果表明，最大拉伸应力与电解质的非化学计量有关。计算还表明，应允许自支撑平面电解质通过弯曲来松弛，以使断裂的风险最小化，并且支撑电解质应尽可能薄。计算表明，在阳极氧活度为10（-20）时，Ce0.8Gd0.2O1.9-δ的最大“安全”工作温度约为750 ℃。在计算中所作的假设的局限性进行了讨论。
Cerium oxide doped with gadolinium is an attractive electrolyte material for solid oxide fuel cells (SOFCs) operating in the temperature range 500-800 degrees C. Under the low oxygen activity conditions of the SOFC anode the ceria is partially reduced and its lattice parameter increases leading to the generation of stress in the electrolyte. These stresses have been calculated for a range of different parameters (Gd doping level, temperature, oxygen activity and cell current) and for different geometrical configurations of an initially planar electrolyte membrane (self-supported or supported on a porous substrate). The calculations show how the maximum tensile stresses are related to the non-stoichiometry of the electrolyte. The calculations also show that self supporting planar electrolytes should be allowed to relax by bending in order to minimise the risk of fracture and that supported electrolytes should be made as thin as possible. The calculations indicate that the maximum 'safe' operating temperature for Ce0.8Gd0.2O1.9-delta at an anode oxygen activity of 10(-20) is about 750 degrees C. The limitations of assumptions made in the calculations are discussed.