Improved Performance and Stability of Ni-Free Anode Materials for Intermediate Temperature-Solid Oxide Fuel Cells

Abstract

Solid oxide fuel cells (SOFCs), which convert the chemical energy to electrical energy through electrochemical processes, have been considered as highly promising power generation devices, because they have numerous advantages, such as high conversion efficiency, low greenhouse gas emission, multi-fuel capability and high tolerance to fuel impurities. These days, the most commonly used anode materials are Ni-based cermets due to their excellent electrocatalytic properties for fuel oxidation. However, Ni-based cermets suffer chemical and physical performance degradations caused by the carbon deposition when hydrocarbon gases use as the anode fuel. Furthermore, Ni-based cermets are exposed to the severe mechanical stresses under the fuel starvation condition due to the volume expansion of the anode by the Ni oxidation to NiO. Hence in order to resolve these reliability issues of the Ni-based cermet anode, more durable Ni-free anode materials with good electrocatalytic properties are developed. Among these, (La,Sr)(Cr,Mn)O3- δ (LSCM) materials have considered as an alternative of Ni-based cermet anode because of high stability under H2 and CH4 conditions. However, LSCM shows low electrocatalytic activity for fuel oxidation because of its low ionic and electronic conductivity. Hence, various materials are doped to LSCM to improve electrocatalytic activity and thus resulting in improving the SOFC performance with high stability.