Ca_3−xLa_xCo₄O_9+δ (x=0, 0.3): New cobaltite materials as cathodes for proton conducting solid oxide fuel cell

Hamdi Ben Yahia (1) , Fabrice Mauvy (1) , Jean-Claude Grenier (1)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Misfit-type Ca_3−xLa_xCo₄O_9+δ (x=0, 0.3) oxides were synthesised to be evaluated as possible cathode materials for proton conducting fuel cells (PCFCs) based on BaCe_0.9Y_0.1O_3−δ (BCY10) dense ceramic electrolyte. The electrical conductivity value of Ca_2.7La_0.3Co₄O_9+δ (σ≈53 S cm^–1 at 600 °C) is in the range of usually required value for a cathode application (about 50–100 S cm^–1). In order to test the performance of each compound as cathode material, impedance measurements were carried out on Ca_3−xLa_xCo₄O_9+δ/BaCe_0.9Y_0.1O_3−δ/Ca_3−xLa_xCo₄O_9+δ symmetrical half cells over the temperature range 400–800 °C under wet air. A promising electrocatalytic activity has been observed with both compounds Ca₃Co₄O_9+δ and Ca_2.7La_0.3Co₄O_9+δ. Factually, the area specific resistance obtained was about 2.2 Ω cm² at 600 °C.

Mots clés: Layered cobaltite oxide; Cathode; Proton conductor; PCFC; Y-doped BaCeO₃

Domaines: Matériaux

Hamdi Ben Yahia, Fabrice Mauvy, Jean-Claude Grenier. Ca_3−xLa_xCo₄O_9+δ (x=0, 0.3): New cobaltite materials as cathodes for proton conducting solid oxide fuel cell. Journal of Solid State Chemistry, 2010, 183 (3), pp.527-531. ⟨10.1016/j.jssc.2009.12.014⟩. ⟨hal-00467042⟩