Proton Conduction and Electrochemical Performance of La/Pr co-Doped Ceria Electrolyte in Ceramic Fuel Cell

La/Pr co-doped ceria (LCP) is processed to fabricate low-temperature ceramic fuel cell based on industrial-grade rare-earth carbonate electrolyte that is reached above a maximum power density of 750 mW/cm 2 at 520 °C. The charge carriers are investigated through LCP fuel cell having symmetric NCAL (Ni 0.8 Co 0.15 Al 0.05 LiO 2-δ ) electrodes using proton conductor BCZY (BaCe 0.7 Zr 0.1 Y 0.2 O 3-δ ) as a blocking layer and are found protons that dominate during the cell operation. The results of associated characterizations for HCC (hydrogen concentration cell) and the OCC (oxygen concentration cell) reveal that LCP material is mixed conductor of both protons and oxygen ions simultaneously. Transmission electron microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) analysis before and after the electrochemical testing of the cell are performed which show an amorphous layer of LiOH/Li 2 CO 3 mixture that is formed after the tests on the surface of LCP structure. Conceptually, it looks that LiOH/Li 2 CO 3 mixture in molten state in the interface region of two-phase material promotes the proton conduction through LCP electrolyte, with negligible oxygen ion conduction.