Physical principles for the calculation of equilibrium potential for co-electrolysis of steam and carbon dioxide in a Solid Oxide Electrolyzer Cell (SOEC)
Physical principles for the calculation of equilibrium potential for co-electrolysis of steam and carbon dioxide in a Solid Oxide Electrolyzer Cell (SOEC)
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DOI：
10.1016/j.electacta.2014.09.144
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发表时间：
2014-11
影响因子：
6.6
通讯作者：
Jan Pawel Stempien;Jan Pawel Stempien;Qinglin Liu;Qinglin Liu;M. Ni;Qiang Sun;S. Chan;S. Chan-S.-Ch
中科院分区：
文献类型：
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作者：
Jan Pawel Stempien;Jan Pawel Stempien;Qinglin Liu;Qinglin Liu;M. Ni;Qiang Sun;S. Chan;S. Chan-S.-Ch
本文对固体氧化物电解槽中H_2O和CO_2共电解的平衡电位（也称为开路电压）的计算进行了比较研究。我们从彻底检查文献和调查的物理原理，这种电位差的发展。在此基础上，我们比较了三种不同模型的使用。标准模型是指使用能斯特方程来描述燃料电极的反应H2O/H2或CO2/CO。氧分压模型是指使用能斯特方程来描述电池两端的氧分压差。混合势模型是指Fleming等人描述的现象，称为混合势理论（MPT），即可观测的电势差是所有上述电势差的叠加。我们的结论是，氧分压模型足以在800 °C以上的温度下操作的现代电池，如果在气体混合物中的CO2的浓度低于25%。在此极限以上，MPT模型更准确，因此推荐使用。标准模型在所有情况下都显示出较大的误差，因此不推荐使用。本文还给出了与MPT模型相结合的参数值，并对800 °C下工作的Ni-YSZ燃料电极电池进行了拟合。
This paper reports a comparative study on the calculation of equilibrium potential (also known as Open Circuit Voltage) of co-electrolysis of H2O and CO2in a Solid Oxide Electrolyzer Cell. We start with the thorough examination of literature and investigation of physical principles governing the development of such a potential difference. Based on that review, we compare the use of three different models. A standard model refers to the use of Nernst equation for fuel electrode's reaction H2O/H2or CO2/CO. An oxygen partial pressure model refers to the use of Nernst referring to oxygen partial pressure difference across the cell. A mixed potential model refers to the phenomena described by Fleming et al. as the Mixed Potential Theory (MPT), i.e. the observable potential difference is the superposition of all above potential differences. We conclude that the oxygen partial pressure model suffices for modern cells operated at temperature above 800 °C and if the concentration of CO2in the gas mixture is below 25%. Above this limit, MPT model is more accurate and thus recommended. The standard model exhibit large error in all cases and is not recommended. We also present the values of parameters, used in conjugation with MPT model, fitted to a cell with Ni-YSZ fuel electrode operated at 800 °C.