A Study of Three-Phase Boundary Inserting ZnO in a LSF-YSZ Cell for a Solid Oxide Fuel Cell

摘要

Different lanthanum and strontium based electrode compositions for solid oxide fuel cells with varying proportions of zinc, iron etc. have been fabricated ((La_(0.6)Sr_(0.4))_(0.98)Zn_xFe_(1-x)O_(3-δ)). The electrodes have been impregnated with catalysts to enhance electrochemical reactions [1, 2]. The sharp peaks in the XRD data indicate a very good phase formation of the LSZF and this is also same is confirmed by SEM images which show a fine granular morphology. Very less study is available in the literature about the electrical properties of LSZF samples for usage in SOFCs. The LSZF samples exhibiting interfacial resistance in the region of a maximum of about 16 Ωcm~2 to a minimum of 1 Ωcm~2 at a temperature range of 750 °C to 600 °C. A maximum power density of 0.5 W/cm~2 is obtained at 800 °C for the LSZF sample with impregnated catalyst. Results have been compared with similar electrode compositions. It has shown to be of comparable or better than existing LSF or other lanthanum-strontium doped ferrites. Results indicate that impedance decreases with increasing temperature. The addition of zirconia is expected to enhance the stability of the electrode by allowing microstructure refinement and providing mechanical support to the electrode.