Analytical model for concentration/pressure (zeta) impedance of the cathode side of a PEM fuel cell is developed. The model is based on transient oxygen mass transport equations through the gas-diffusion and cathode catalyst layers. Analytical solution for zeta-impedance is derived and the relation of zeta-impedance and regular cell impedance is obtained. In the limit of high oxygen consumption in the catalyst layer, simple equations for the static point of zeta impedance are derived. These equations allow one to estimate oxygen transport coefficients of the catalyst and gas diffusion layers from the static point of zeta-spectrum. Qualitative resemblance of the model and experimental zeta-spectrum is demonstrated.

开发了 PEM 燃料电池阴极侧的浓度/压力 (zeta) 阻抗分析模型。该模型基于通过气体扩散和阴极催化剂层的瞬态氧传质方程。推导出zeta-阻抗的解析解，得到zeta-阻抗与规则单元阻抗的关系。在催化剂层耗氧量高的限制下，导出了zeta阻抗静点的简单方程。这些方程允许人们从 zeta 光谱的静态点估计催化剂和气体扩散层的氧传输系数。证明了模型和实验 zeta 光谱的定性相似性。