FEM Model-Based Design Optimization of a Planar SOFC Interconnector Flowfield

Solid Oxide Fuel Cells often show a significant power loss when integrated in a bipolar stack. In this paper, power limiting factors related to the inhomogeneity of current collection and gas supply are analyzed by means of a Finite Element Method model. The model, which considers the coupling of electronic and ionic charge carrier transport, charge transfer reactions and diffusive gas transport, provides the spatial distribution of the related losses and their dependency on operating conditions, cell- and flowfield-design. Simulation studies proved that in plane gas diffusion losses underneath the contact rib as well as ohmic losses in the cathode underneath the gas channel affect the performance. Variations in flowfield design parameters revealed optimum parameter combinations, which depend on the chosen operating conditions. For technically feasible flowfield design parameters performance losses of approximately 15% are predicted by the model.