Comparative study of solid oxide fuel cells supported on ceramic cathodes with different pore structures. (6th April 2021) - Sun, Le
Abstract: The present study was intended to investigate the performance dependence of the solid oxide fuel cells on the pore structure of the supporting cathode. The Sr-doped lanthanum manganite/yttria-stabilized zirconia electrodes with different pore structures were prepared, and their inner surfaces were modified with nano-scale Sm0.2 Ce0.8 O1.95-δ (SDC). The cell supported on the electrode with a straight pore structure demonstrated much higher maximum power densities than the one supported on the electrode with a tortuous pore structure, e.g., 652 vs 308 mW cm −2 at 800 °C. Impedance analysis revealed that the straight pore structure together with SDC-modified pore surface not only promoted the surface oxygen exchange, but also enhanced the transport of oxygen species to the reaction sites and conduction of oxide ions and electrons in the electrode. The ceramic cathode-supported cell survived 20 redox cycles, showing much better stability than the cermet anode-supported cell. Further research on the supporting cathode is needed to increase the power output density required for practical applications. Graphical abstract: The SOFC supported on a LSM-YSZ supporting electrode with a straight pore structure demonstrated a much increased maximum power density over the one on the electrode with a tortuous pore structure, which was attributed to the reduced polarization resistance and ohmic resistance of the electrode. Image 1 Highlights: A cathode with a straight pore structure and catalyst-modified pore surface was prepared. The cathode showed much reduced interfacial polarization and ohmic resistance. The cell supported on the cathode demonstrated much increased power densities. The cell survived 20 redox cycles, showing excellent stability.