Effect of coating solution concentration on electrochemical properties of La_0.8Sr_0.2MnO₃-coated La_0.8Sr_0.2FeO₃ electrodes

La_0.8Sr_0.2MnO₃ (LSM)-coated La_0.8Sr_0.2FeO₃ (LSF) electrodes were prepared via the infiltration of LSM stock solution with different concentrations (0.005, 0.010, 0.020, 0.035 and 0.040 mol/L) into porous LSF electrode. The effect of coating solution concentration on the electrochemical performance was investigated. The results obtained by X-ray diffraction indicated there was no reaction between the LSM and LSF in the LSM-coated LSF electrode. The thickness of coating and the grain size increased with the increase of LSM concentration. The porous LSF electrode coated with LSM solution of 0.010 mol/L exhibited an optimum performance under anodic polarization and the polarization resistance was 0.3 Ω·cm² at 800°C. Moreover, The polarization resistance variation of the LSM-coated LSF electrode was independent of the polarization directions, and decreased under both cathodic and anodic polarizations in a short-term (1 200 s). The LSM electrocatalytic activity of the electrode surface played an important role in the performance enhancement. The LSM-coated LSF electrode with 0.010 mol/L LSM solution could be a promising anode material for solid oxide electrolysis cell.