Sr- and Ba- doped LaCuO_(3-Δ) perovskites with mixed ionic-electronic conductivity as IT-SOFC cathode materials

摘要

Due to the well-known excellent electrical conductivity and substantial deviation from the oxygen nonstoichiometry, LaCuO_(3-Δ)-based perovskite-type cuprates may be considered as alternative, promising candidate cathode materials for application in IT-SOFCs. In this work, investigations of the phase composition, crystal structure at room and high temperatures, oxygen nonstoichiometry, thermal and chemical stability, as well transport properties for the selected La_(1-x)(Sr,Ba)_xCuO_(3-Δ) perovskites are presented. The proposed introduction of Sr~(2+) and Ba~(2+) cations allowed to obtain thermally-stable materials (Fig. 1a) with good transport properties. Studies have been supplemented with tests of the electrochemical performance of LSGM-electrolyte supported IT-SOFC with analyzed oxides used as the cathode. The most promising electrochemical performance was obtained for La4BaCu5O_(15-Δ) (LBC, Fig. 1b), for which power density reached 0.5 W cm~(-2) at 900 °C while the cell was fueled with wet hydrogen.