A high-performance solid oxide fuel cell anode based on lanthanum strontium vanadate

Abstract

Ceramic composites were prepared by infiltration of La_0.7Sr_0.3VO_3.85 (LSV) into porous scaffolds of yttria-stabilized zirconia (YSZ) and tested for use as solid oxide fuel cell (SOFC) anodes. There was no evidence for solid-state reaction between LSV and YSZ at calcination temperatures up to 1273 K. For calcination at 973 K, LSV formed a continuous film over the YSZ. The LSV phase reduced easily upon heating in H₂ to 973 K, with the reduction forming pores in the LSV and greatly increasing its surface area. The electrodes showed high electronic conductivity after reduction, with a 10-vol% LSV–YSZ composite exhibiting a conductivity of 2 S cm⁻¹ at 973 K. In the absence of an added catalyst, the LSV–YSZ electrodes showed relatively poor performance; however, an electrode impedance of approximately 0.1 Ω cm² was achieved at 973 K in humidified H₂ following addition of 0.5 vol% Pd and 2.8 vol% ceria The LSV–YSZ composites were stable in CH₄ but there was evidence for poisoning of the Pd catalyst by V following high-temperature oxidation.