Reliability and accuracy of measured overpotential in a three-electrode fuel cell system
Reliability and accuracy of measured overpotential in a three-electrode fuel cell system
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三电极燃料电池系统中测量过电势的可靠性和准确性
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
K. Khor
中科院分区：
文献类型：
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作者：
S. Chan;X. J. Chen;K. Khor
通过数值模拟研究了固体氧化物燃料电池活性电极表面的电位和电流密度分布。研究了电极偏差、电解液厚度和电极极化电阻对测量误差的影响。对于同轴阳极/电解液/阴极系统，当阳极半径大于阴极半径时，阴极过电位被高估，而阳极过电位被低估。虽然电流中断法或阻抗谱法可以用来补偿/纠正对称电极配置的误差，但它在处理不对称电极系统时是无用的。为了表征燃料电池中各自的过电位，必须仔细设计电池结构，以尽量减少测量误差，特别是电解质厚度的选择，这可能会导致显著的误差。对于阳极支撑的单燃料电池，参考参考电极很难区分阳极和阴极的极化。然而，数值结果可以大致了解测量误差的来源和原因，并为燃料电池的设计提供依据，以提高测量技术的可靠性和准确性。
Numerical simulation was conducted to study the potential and current density distributions at the active electrode surface of a solid oxide fuel cell. The effects of electrode deviation, electrolyte thickness and electrode polarization resistance on the measurement error were investigated. For a coaxial anode/electrolyte/cathode system where the radius of the anode is greater than that of cathode, the cathode overpotential is overestimated while the anode overpotential is underestimated. Although the current interruption method or impedance spectroscopy can be employed to compensate/correct the error for a symmetric electrode configuration, it is not useful when dealing with the asymmetric electrode system. For the purpose of characterizing the respective overpotentials in a fuel cell, the cell configuration has to be carefully designed to minimize the measurement error, in particular the selection of the electrolyte thickness, which may cause significant error. For the anode-support single fuel cell, it is difficult to distinguish the polarization between the anode and cathode with reference to a reference electrode. However, numerical results can offer an approximate idea about the source/cause of the measurement error and provide design criteria for the fuel cell to improve the reliability and accuracy of the measurement technique.