Efficient symmetrical electrodes based on LaCrO3 via microstructural engineering

Novel nanostructured electrodes, La0.98Cr0.75B0.25O3 delta (B = Mn, Fe, Ti and Cu), are prepared by a single spray-pyrolysis deposition method directly on the electrolyte and a porous Ce0.9Gd0.1O1.95 (CGO) scaffold. These perovskite-type electrodes without alkaline-earth metals exhibit low ionic/electronic conductivity; however, the polarization resistance is greatly enhanced by microstructural design. The best results are obtained for La0.98Cr0.75Mn0.25O3-delta deposited into a porous CGO-scaffold due to the synergetic effect of CGO, with high ionic conductivity, and doped-LaCrO3 with a predominantly electronic conductivity. The materials are investigated as both air and fuel electrodes for solid oxide fuel cells (SOFCs) by different structural, microstructural and elec-trochemical techniques. Low values of polarization resistance are achieved for nanostructured La0.98Cr0.75Mn0.25O3-delta-CGO electrodes, i.e. 0.057 S-2 cm(2) in air at 800 degrees C, compared to 0.96 S-2 cm(2) for the same powder electrode obtained by screen-printing deposition. An electrolyte-supported symmetrical cell generates a stable maximum power output of 475 mW cm(-2) at 800 degrees C.

Automated summary

Novel nanostructured electrodes have been prepared using a spray-pyrolysis deposition method, leading to lower polarization resistance in solid oxide fuel cells. The La0.98Cr0.75Mn0.25O3-delta-CGO electrodes showed significantly lower polarization resistance in air at 800 degrees Celsius.