Phase field modeling of microstructure evolution of electrocatalyst-infiltrated solid oxide fuel cell cathodes

Articles you may be interested in Microstructural coarsening effects on redox instability and mechanical damage in solid oxide fuel cell anodes Redox instability, mechanical deformation, and heterogeneous damage accumulation in solid oxide fuel cell anodes J. Phase-field modeling of three-phase electrode microstructures in solid oxide fuel cells Appl. Synthesis and calorimetric studies of oxide multilayer systems: Solid oxide fuel cell cathode and electrolyte materials J. A phase field model is developed to examine microstructural evolution of an infiltrated solid oxide fuel cell cathode. It is employed to generate the three-phase backbone microstructures and morphology of infiltrate nano-particles [La 1Àx Sr x MnO 3 (LSM)]. Two-phase Y 2 O 3 þ ZrO 2 and LSM backbones composed of 0.5–1 lm particles are first generated and then seeded with infiltrate, and evolution is compared for starting infiltrate particle diameters of 5 nm and 10 nm. The computed lifetime triple phase boundary (3PB) density of the infiltrated cathode is then compared to the cathode backbone. Results indicate that initial coarsening of infiltrate nano-particles is the primary evolution process, and infiltrate coarsening is the majority contributor to 3PB reduction. However, at all times, the infiltrated cathode possesses significantly greater 3PB length than even the uncoarsened backbone. Infiltrate particle size effects indicate that the smaller particle size produces greater 3PB length for the same infiltration amount, consistent with intuition. A maximum 3PB enhancement is reached when increasing infiltrate particle loading, and the maximum enhancement depends on infiltrate particle size. It is found that architectural degradation modes will insignificantly affect the lifetime performance of infiltrated cathodes. This work suggests that lifetime optimized particle size/loading combinations are identifiable, and can be precise if additional fundamental data become available.