Plasma Sprayed Oxygen Electrode for Solid Oxide Fuel Cells and High Temperature Electrolyzers

Abstract

Perovskite-type LSM and LSCF deposits were developed for oxygen electrode for solid oxide fuel cell and high temperature water electrolyzer by atmospheric plasma spraying (APS) using different feedstock powders. The deposits were tailored to exhibit high oxygen catalytic activity, oxygen surface exchange and diffusion rates, gas permeability and electronic-ionic conductivity. Deposits did not exhibit undesired secondary phases that may form in plasma. Promoting partial melting of the surface of the particles ensured interlayer cohesion and very porous deposit. In SOFC mode cells with LSCF cathodes operating at 800 °C had more than 700 mW/cm² power densities at 0.7 V, which was 35% better than that of cells with LSM cathode. When operating in electrolyzer mode at 800 °C the cells with LSCF oxygen electrode also proved significantly enhanced electrochemical performance compared to cells with LSM oxygen electrode. At a current density of 1 A/cm2 the voltage for water splitting was reduced to around 1.4 V at an operating temperature of 800 °C and to 1.28 V at 850 °C.