Macroscopic properties of solid oxide fuel cell electrodes via microstructure-based numerical homogenization

Abstract

Due to climate change, sustainable and energy-efficient power supply is urgently required. To increase the performance of solid oxide fuel cells, the effects of the microstructure of their porous electrodes need to be studied. Therefore, real tomography images are used to (i) characterize specific geometrical features such as the two-point correlation function or the tortuosity and (ii) determine the effective conductivities (thermal, ionic, electronic) and the effective permeability. The temperature-dependent and anisotropic physical properties based on the first-order homogenization method are described by the dissipation potential. The results can be used in macroscopic fuel cell simulations to bridge the gap between the micro and macro scale and to gain a better understanding of which characteristics of electrode microstructures are favorable for higher efficiency.