Synthesis and Evaluation of LaBaCo_2−<i>x</i>Mo<i>_x</i>O_5+<i>δ</i> Cathode for Intermediate-Temperature Solid Oxide Fuel Cells

Abstract

LaBaCo2−xMoxO5+δ (LBCMx, x = 0–0.08) cathodes synthesized by a sol-gel method were evaluated for intermediate-temperature solid oxide fuel cells. The limit of the solid solubility of Mo in LBCMx was lower than 0.08. As the content of Mo increased gradually from 0 to 0.06, the thermal expansion coefficient decreased from 20.87 × 10−6 K−1 to 18.47 × 10−6 K−1. The introduction of Mo could increase the conductivity of LBCMx, which varied from 464 S cm−1 to 621 S cm−1 at 800 °C. The polarization resistance of the optimal cathode LBCM0.04 in air at 800 °C was 0.036 Ω cm2, reduced by a factor of 1.67 when compared with the undoped Mo cathode. The corresponding maximum power density of a single cell based on a YSZ electrolyte improved from 165 mW cm−2 to 248 mW cm−2 at 800 °C.

Keywords

• solid oxide fuel cell
• perovskite cathode
• thermal expansion coefficient
• electrical conductivity
• electrochemical performance