Effects of Bi2O3 doping on structural and electrical properties of Ce0.8Sm0.2O1.9 electrolyte for solid oxide fuel cells

The study investigates the impact of Bi 2 O 3 doping on the crystal structure, density, and ionic conductivity of Ce 0.8 Sm 0.2 O 1.9 , a type of samarium-doped ceria oxide (SDC). The material is intended for use as a solid electrolyte in intermediate temperature solid oxide fuel cells (IT-SOFCs). The SDC-based electrolyte was created using the auto-combustion technique, with various molar ratios of Bi 2 O 3 . Phase compositions, microstructure, and ionic conductivity of all ceria ceramics were analysed using XRD, SEM and impedance analyses, respectively. The language is formal, clear, objective, and value-neutral, using high-level, standard language with consistent technical terms. Grammar, spelling, and punctuation are correct. Consistent citation and footnote style are maintained. The samples are single-phase ceramics that crystallise into a cubic fluorite type structure with space group Fm-3 m, as confirmed by the X-ray diffraction pattern. Technical abbreviations are explained. The structure ensures a logical flow of information with causal connections between statements. No filler words or biased language are used. SDC/Bi 2 O 3 composite powders exhibit high sintering activity. The relative density of all samples sintered at 1300 ºC for 5 h was more than 96%, which is higher than that achieved by pure SDC electrolyte sintered at 1400 ºC (94.06%). Electrochemical performance results demonstrate that adding an appropriate amount of Bi 2 O 3 can significantly enhance the conductivity of SDC materials. The SDC-based electrolyte containing 9 mol% of Bi 2 O 3 (SDCB9) demonstrates the maximum conductivity of 43.5 mS·cm −1 at 800 °C, surpassing that of pure SDC which measures 26.86 mS·cm −1 .