Electrochemical Characterization of Columnar Anodic Thin Films Deposited By Pulsed Laser Deposition

(La_0.75Sr_0.25)_0.95Cr_0.5Mn_0.5O_3-∂ (LSCM) is a promising redox-stable material for solid oxide fuel cell (SOFC) anodes with hydrocarbon fuels. LSCM requires additional catalysts to boost the anodic performance due to a relatively low electrochemical activity for hydrocarbon oxidation. Nickel, which is usually employed as the catalyst, provokes coking and degrades with sulphur. Therefore, an alternative approach to reduce the area specific resistance (ASR) needs to be devised, such as to significantly increase the density of the triple phase boundary (TPB) sites.  

A solution can be to create an anode with vertically aligned columns with submicron diameter. To reach this goal, thin films of vertically aligned LSCM columns were deposited by pulsed laser deposition (PLD). Initially, LSCM was deposited on Si wafers to optimize the columnar morphology. Then LSCM anodes were deposited on Sm_0.2Ce_0.8O_2-∂ (SDC) pellets and were subjected to heat treatments under ambient and reducing atmospheres. The morphology of the samples was characterized using scanning electron microscopy (SEM). Electrochemical impedance spectroscopy measurements were performed to investigate the anode performance under H₂ and CH₄ environments.