Topology optimization of the microstructure of solid oxide fuel cell cathodes

Thermal mismatch significantly influences the stress state and lifetime of solid oxide fuel cells (SOFCs). The microstructure of the LSM–YSZ cathode is optimized by using the asymptotic homogenization method and three-phase material topology optimization to improve thermal mismatch. Two orthogonal microstructures are obtained by taking minimum thermal mismatch as the object with some constraints. The microstructures constitute a cathode in the form of periodic fiber bundles. Results show that the coefficients of the thermal expansion of the microstructures are almost equal to those of the electrolyte layer at different temperatures, thus eliminating thermal mismatch. The microstructures have higher effective ion conductivity than typical cathodes. The optimization results are helpful for the design of future electrodes.