Characterization of doped La0.7A0.3Cr0.5Mn0.5O3 − δ (A = Ca, Sr, Ba) electrodes for solid oxide fuel cells

Doped lanthanum manganese chromite based perovskite, La0.7A0.3Cr0.5Mn0.5O3 − δ (LACM, A = Ca, Sr, Ba), on yttria-stabilized zirconia (YSZ) electrolyte is investigated as potential electrode materials for solid oxide fuel cells (SOFCs). The electrical conductivity and electrochemical activity of LACM depend on the A-site dopant. The best electrochemical activity is obtained on the La0.7Ca0.3Cr0.5Mn0.5O3 − δ/YSZ (LCCM/YSZ) composite electrodes. The conductivity of LCCM is 29.9 S cm− 1 at 800 °C in air, and the electrode polarization resistance (RE) of the LCCM/YSZ composite cathode for the O2 reduction reaction is 0.5 Ω cm2 at 900 °C. The effect of Gd-doped ceria (GDC) impregnation on the LCCM cathode polarization resistances is also studied. GDC impregnation significantly enhances the electrochemical activity of the LCCM cathode. In the case of the 6.02 mg cm− 2 GDC-impregnated LCCM cathode, RE is 0.4 Ω cm2 at 800 °C, ~ 60 times smaller than 24.4 Ω cm2 measured on a LCCM cathode without the GDC impregnation. Finally the electrochemical activities of the doped lanthanum manganese chromites for the H2 oxidation reaction are also investigated.