Fabrication and electrochemical performance of La0.595V0.005Sr0.4MnO3−δ (LV05SM) cathode material for solid oxide fuel cells

Abstract

This study reports the effect of vanadium on the crystal structure and electrical and electrochemical properties of La 0.6−x Vx Sr 0.4 MnO3−δ (x = 0.005–0.1) perovskite-based cathode materials in solid oxide fuel cells. Crystalstructure, morphology, and porosity of prepared cathode materials are characterized by X-ray diffraction, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy. Using XPS analysis it was established that the La 3+cation is exchanged by the V4+/5+ cation in the perovskite structure. This ion replacement improves the ionic conductivity and catalytic activity for oxygen reduction reaction in the perovskite structure, presumably due to the smallersize of the V4+/5+ cation than the La 3+ ion. Oxygen partial pressure-related polarization experiments suggest that theadsorption-desorption process and the reactions controlled by the atomic oxygen diffusion process followed by chargetransfer are the cathode reaction rate-limiting steps.