CGO as a barrier layer between LSCF electrodes and YSZ electrolyte fabricated by spray pyrolysis for solid oxide fuel cells

Abstract

Perovskite La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) is often used as a cathode material for solid oxide fuel cells (SOFC) due to high mixed ionic and electronic conductivity and good catalytic activity. Unfortunately, sintering of the LSCF cathode together with the yttria stabilized zirconia (YSZ) electrolyte, leads to formation of the La2Zr2O7 and SrZrO3 phases in the interface. These phases increase the resistance of the cell. To avoid creation of the undesirable phases, diffusion barrier layers are often used. In this work 200nm thick cerium-gadolinium oxide (CGO) layer deposited by spray pyrolysis is used as a diffusion barrier. The impact of sintering temperature on the effectiveness of diffusion barrier was examined. For optimized sintering temperature of 900°C, the CGO barrier layer leads to lowering polarization loses of almost two orders of magnitude from 477mΩcm2 (when CGO is not used) to 7mΩcm2.