Influence of Ce0.8R0.2O2-a (R = Y, Sm, Tb) submicron barrier layers at the La2NiO4+δ/YSZ boundary on the electrochemical performance of a cathode

Ce0.8R0.2O2-a (R = Y, Sm, Tb) (further Ce20R) submicron barrier layers, which were obtained by the dip-coating method on a YSZ (ZrO2 + 9.5 mol.% Y2O3) solid electrolyte to prevent the chemical interaction between YSZ and the La2NiO4+delta-based cathode material, were studied. The final thermal treatment of the barrier layers was performed at 1200 degrees C. A porous composite of the La2NiO4+delta-Ce0.8Sm0.2O2-a composition with the LaNi0.6Fe0.4O3 collector layer served as the cathode. The polarization characteristics of the cathodes were studied by impedance spectroscopy for both the uncoated electrolyte and the electrolyte with Ce20R (R = Sm, Tb, Y) thin-layer coatings of various thicknesses. The impedance spectra were analyzed using the DRT method. Even single-layer coatings (approximate to 200 nm) were found to prevent the chemical interaction between the electrode and the electrolyte and to greatly increase (by 5.5-6 orders of magnitude) the electrode polarization conductivity.

Automated summary

By preparing Ce20R submicron barrier layers on YSZ solid electrolyte, the chemical interaction between the electrode and the electrolyte can be prevented effectively, greatly increasing the electrode's polarization conductivity.