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oai:riuma.uma.es:10630/394432026-02-03T11:34:26Zcom_10630_2254col_10630_37953

00925njm 22002777a 4500 dc Sánchez Caballero, Abraham author Dos-Santos-Gómez, Lucía author Zamudio-García, Javier author Porras-Vázquez, José Manuel author Marrero-López, David author 2025-07-09 This study explores how high-valence dopants affect the structural, thermal, and electrochemical properties of (Pr0.5Ba0.5)0.98Fe0.9M0.1O3-δ (M = Ga3+, Ti4+, Zr4+, Nb5+, Mo6+, W6+, and Re7+) for SOFC air electrodes. Thermogravimetric analysis reveals that increasing the dopant oxidation state reduces oxygen loss upon heating, indicating improved stability of the oxygen sublattice. Consistently, dilatometric measurements show a decrease in the thermal expansion coefficients from 22.3 × 10-6 K-1 for Ga3+-doped to 15.1 × 10-6 K-1 for W6+-doped samples. Impedance spectroscopy further confirms a clear correlation between dopant oxidation state and electrode polarization resistance, with values slightly increasing from 0.14 Ω cm2 for (Ga3+) to 0.21 Ω cm2 (W6+) at 700 ºC. These findings demonstrate that while high-valence doping improves structural stability and reduces thermal expansion, it does not necessarily enhance the oxygen reduction reaction activity. Overall, this study provides key insights into doping strategies to optimize SOFC air electrodes by balancing stability, thermal compatibility, and performance. Journal of the European Ceramic Society 45 (2025) 117657 https://hdl.handle.net/10630/39443 10.1016/j.jeurceramsoc.2025.117657 Pilas de combustible Conversión directa de la energía Tailoring the thermal expansion and electrochemical properties of Pr0.5Ba0.5FeO3-δ electrodes through high-valence cation doping for SOFCs