Characterization of nanosized Ce0.8Sm0.2O1.9-infiltrated Sm0.5Sr0.5Co0.8Cu0.2O3−δ cathodes for solid oxide fuel cells

This study investigates the microstructure and electrochemical properties of Sm0.5Sr0.5Co0.8Cu0.2O3−δ (SSC-Cu) cathode infiltrated with Ce0.8Sm0.2O1.9 (SDC). The newly formed nanosized electrolyte material on the cathode surface, leading the increase in electrochemical performances is mainly attributed to the creation of electrolyte/cathode phase boundaries, which considerably increases the electrochemical sites for oxygen reduction reaction. Based on the experiment results, the 0.4 M SDC infiltration reveals the lowest cathode polarization resistance (RP), the cathode polarization resistances (Rp) are 0.117, 0.033, and 0.011 Ω cm2 at 650, 750, and 850 °C, and the highest peak power density, are 439, 659, and 532 mW cm−2 at 600, 700, and 800 °C, respectively. The cathode performance in SOFCs can be significantly improved by infiltrating nanoparticles of SDC into an SSC-Cu porous backbone. This study reveals that the infiltration approach may apply in SOFCs to improve their electrochemical properties.

► The SDC-infiltrated SSC-Cu cathode with numerous sites for oxygen reduction reaction.
► The dramatic decrease in cathode polarization resistance for SDC-infiltrated SSC-Cu cathode was mainly attributed to the creation of SDC/SSC-Cu phase boundaries.
► The newly formed SDC on the SSC-Cu surface with highly porous would allow gas-phase molecules to easily diffuse.