The effect of the cell voltage and external conditions on the characteristics of protonic ceramic fuel cells is theoretically elucidated taking into account the non-uniform distribution of charge carriers along and across the oxide membrane with proton and hole conductivity. The interdependence of this distribution and gas phase composition along the cathode and anode gas channels is a fundamental feature of fuel cells based on proton-conducting oxides. To address this issue, a novel computational method is proposed to determine the current densities and effective characteristics of the fuel cells operating on wet hydrogen and oxygen. It is shown that the effective proton conductivity can either increase or decrease with increasing the cell voltage depending on the fuel and oxidant humidity. In contrast, the effective hole conductivity drastically increases with increasing the cell voltage for any realistic gas phase compositions, thereby reducing the proton transport number and faradaic efficiency. It is demonstrated that the fuel cell parameters (partial conductivities, transport numbers, EMF, etc.) can be noticeably different under open circuit and operating conditions. The established relationships between the cell voltage, parameters of the inlet gas phases and output characteristics can be used as a guide to enhance the performance of protonic ceramic fuel cells.

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揭示电池电压和外部条件对质子陶瓷燃料电池特性的影响

从理论上阐明了电池电压和外部条件对质子陶瓷燃料电池特性的影响，考虑到了沿质子和空穴电导率沿着和穿过氧化膜的电荷载流子的不均匀分布。沿着阴极和阳极气体通道的这种分布和气相组成的相互依赖性是基于质子传导氧化物的燃料电池的基本特征。为了解决这个问题，提出了一种新颖的计算方法来确定在湿氢气和氧气下工作的燃料电池的电流密度和有效特性。结果表明，取决于燃料和氧化剂的湿度，有效的质子传导率可以随着电池电压的增加而增加或减少。相反，对于任何实际的气相组成，有效空穴电导率都随着电池电压的增加而急剧增加，从而降低了质子传输数和法拉第效率。已证明燃料电池的参数（部分电导率，传输数，EMF，等）在开路和工作条件下可能会明显不同。电池电压，入口气相参数和输出特性之间的已建立关系可以用作增强质子陶瓷燃料电池性能的指南。