Long term stability of porosity gradient composite cathode controlled by electro-static slurry spray deposition

Abstract

Proton conducting fuel cells (PCFCs) have attracted much attention due to the lower activation energy of proton transport at intermediate temperatures. The cathode of PCFCs has been studied for enhancement of cell performance. Unlike solid oxide fuel cells (SOFCs), the product of chemical reaction, H2O, is generated in the cathode region. Generally, as the structure of the PCFC’ cathode is denser than the anode of SOFC, the vapor is not easily emitted outside of the cathode, and this remaining vapor in the isolated cathode structure has a negative effect on cell performance. In this work, a gradient porous La0.6Sr0.4Co0.2Fe0.8O3−δ(LSCF)/BaCe0.7Zr0.15Y0.15O3−δ(BCZY) composite cathode was developed for fuel cells based on the BCZY electrolyte using an electrostatic spray slurry deposition method. The cathode porosity and deposited powder size gradually increased in the direction away from the electrolyte-electrode. The results indicate that the structure of the porosity gradient cathode might enhance the long-term stability in proton conducting fuel cells.