Structural, electrical and electrochemical characteristics of La0.1Sr0.9Co1-xNbxO3-delta as a cathode material for intermediate temperature solid oxide fuel cells

Abstract

The perovskite-oxides, such as (La, Sr)CoO3, have received a large amount of attention in recent years as cathode materials for intermediate temperature-solid oxide fuel cells (IT-SOFCs). In this study, we have investigated the structural, electrical, and electrochemical properties of La0.1Sr0.9Co1-xNbxO 3-δ (x = 0, 0.1, 0.15, and 0.2) cathodes under IT-SOFC operating conditions. Nb doping significantly improves the structural stability and electrochemical performance of La0.1Sr0.9Co 1-xNbxO3-δ (LSCNbx) oxides compared to undoped La0.1Sr0.9CoO3-δ (LSC). At a given temperature, the electrical conductivity decreases with further increases of the Nb doping content. The electrochemical performance of LSCNbx-GDC cathodes is measured using an LSCNbx-GDC/GDC/ Ni-GDC anode supported cell. For LSCNbx (x = 0.1), the maximum power density of a single cell is 1.478 W cm-2 at 600 °C. The Nb doped LSCNbx (x = 0.1) perovskite is recommended, considering its high power density and structural stability as an IT-SOFC cathode material.