Effects of microstructure and phase compatibility in a composite of Ba 0.5La0.5CoO3-δ (BLC) and Pr1.9 (Ni, Cu, Ga)O4+δ (PNCG) with a mass ratio of 5:1 (BP51) on electrochemical properties were investigated with varying firing temperature of the composite as cathode (973-1373 K). Grain growth was observed with increasing firing temperature while single phase was maintained below 1173 K in the composite. Area specific resistance (ASR) of BP51 cathode fired at 1073 K was decreased due to fine particles, intimate contact, and phase purity, leading to enhancement of reactivity on oxygen exchange and diffusion of oxygen species. Moreover, BP51 cathode with small grains revealed improved electrochemical performance compared with that of coarse particles. Accordingly, increased maximum power density of ca. 1.3 and 0.2 Wcm-2 at 973 and 773 K was achieved in an anode supported single cell of Sr- and Mg-doped LaGaO3 (LSGM) electrolyte film with fine BP51 cathode owing to decrease in both electrode polarization and interfacial contact resistance. Furthermore, cell performance was stable under an applied current density of 1.7 Acm-2 at 973 K. This study reveals that fine BP51 composite is a promising cathode for high performance intermediate temperature SOFCs.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry