Influence of Ni concentration on electrochemical and crystallographic properties of La0.25Sr0.25Ca0.4Ti1-xNixO3-δ solid oxide fuel cell anode

In this work, we studied the effects of Ni-doping level on the catalytic activity, stability and mobility of A-site cations of the La0.25Sr0.25Ca0.4TiO3?? (LSCT) fuel electrode. Results indicate that Ni concentration in B-site influences the phase properties, element ratios on the surface, element mobility during preparation, conductive properties and catalytic activity of electrode significantly. The best performance was measured for La0.25Sr0.25Ca0.4Ti0.95Ni0.05O3?? having very low polarization resistance value 0.084 ? cm2 at 850 ?C (at OCV). The results of the experiments indicate excellent stability of the material ? Rp remained stable during the 120 h test. Ni-doping also stabilizes the LSCT structure and makes it more stable in different gas atmospheres and suppresses segregation of CaO to the electrode surface. Moreover, it even suppresses significantly A-site cation mobility during electrode processing, which was one of the most relevant problems with pure LSCT. The accumulation of Sr at the zirconate electrolyte surface and formation of SrZrO3, which was one of the vital issues observed for undoped LSCT, has been avoided in the case of Ni-doped materials.