Cobalt oxide enhanced lanthanum strontium cobalt ferrite electrode for solid oxide fuel cells

Abstract

A Co₃O₄ enhanced La_0.8Sr_0.2Co_0.5Fe_0.5O_3 - δ (LSCF) electrode is developed for use in air electrodes with proton conducting solid oxide fuel cell (SOFC). The incipient wetness impregnation method enables Co₃O₄ nanoparticles on the LSCF surface without altering the bulk porosity of the LSCF electrode. The polarization resistance of LSCF electrodes is significantly reduced by Co₃O₄ doping, and both charge transfer and diffusion/conversion resistances were positively affected. The highest reduction in charge transfer resistance is obtained at 700 °C, which is increased from 21 % to 32 % through reduction of po₂. Conversely, the highest reduction in diffusion/conversion resistance is achieved at 550 °C. By increasing po₂, the reduction is increased from 57 % to 66 % and its activation energy is reduced up to 33 % compared to pure LSCF. The lowest total area specific resistances obtained under air are 1.45 Ω·cm², 2.95 Ω·cm², 6.75 Ω·cm² and 16.45 Ω·cm² at 700 °C, 650 °C, 600 °C and 550 °C, respectively.