Tuning Cu-Content La 1-x Sr x Ni 1-y Cu y O 3-δ with Strontium Doping as Cobalt-Free Cathode Materials for High-Performance Anode-Supported IT-SOFCs.

Cu-content La 1-x Sr x Ni 1-y Cu y O 3-δ perovskites with A-site strontium doping have been tuned as cobalt-free cathode materials for high-performance anode-supported SOFCs, working at an intermediate-temperature range. All obtained oxides belong to the R -3 c trigonal system, and phase transitions from the R -3 c space group to a Pm -3 m simple perovskite have been observed by HT-XRD studies. The substitution of lanthanum with strontium lowers the phase transition temperature, while increasing the thermal expansion coefficient (TEC) and oxygen non-stoichiometry δ of the studied materials. The thermal expansion is anisotropic, and TEC values are similar to commonly used solid electrolytes (e.g., 14.1 × 10 -6 K -1 for La 0.95 Sr 0.05 Ni 0.5 Cu 0.5 O 3-δ ). The oxygen content of investigated compounds has been determined as a function of temperature. All studied materials are chemically compatible with GDC-10 but react with LSGM and 8YSZ electrolytes. The anode-supported SOFC with a La 0.95 Sr 0.05 Ni 0.5 Cu 0.5 O 3-δ cathode presents an excellent power density of 445 mW·cm -2 at 650 °C in humidified H 2 . The results indicate that La 1-x Sr x Ni 1-y Cu y O 3-δ perovskites with strontium doping at the A-site can be qualified as promising cathode candidates for anode-supported SOFCs, yielding promising electrochemical performance in the intermediate-temperature range.