Performance simulation of current/voltage-characteristics for SOFC single cell by means of detailed impedance analysis

We present a zero dimensional stationary model which precisely predicts the current–voltage-characteristics of anode supported SOFC single cells over a wide range of operating conditions. The different kinds of electrode polarization resistances are separated from experimental impedance data by means of a detailed equivalent circuit model developed specifically for the analyzed cell type. The activation losses are modeled by the Butler–Volmer equation, whereas the loss contributions from gas diffusion polarizations are calculated from Fick's law. The partial pressure and temperature dependency of the cathodic and anodic exchange current density could be determined by a fit of semi empirical power law model equations. The exponents c and d for the CO and CO2 partial pressure dependency of the anodic exchange current density are determined independently of each other. This paper presents the modeling results for a wide range of operation parameters as well as their experimental verification.