Structural, electrical and electrochemical characteristics of La0.1Sr0.9Co1−xNbxO3−δ 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 La_0.1Sr_0.9Co_1−xNb_xO_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 La_0.1Sr_0.9Co_1−xNb_xO_3−δ (LSCNb_x) oxides compared to undoped La_0.1Sr_0.9CoO_3−δ (LSC). At a given temperature, the electrical conductivity decreases with further increases of the Nb doping content. The electrochemical performance of LSCNb_x–GDC cathodes is measured using an LSCNb_x–GDC/GDC/Ni–GDC anode supported cell. For LSCNb_x (x = 0.1), the maximum power density of a single cell is 1.478 W cm⁻² at 600 °C. The Nb doped LSCNb_x (x = 0.1) perovskite is recommended, considering its high power density and structural stability as an IT-SOFC cathode material.