Silver Based Perovskite Nanocomposites as Combined Cathode and Current Collector Layers for Solid Oxide Fuel Cells

Properties of silver at elevated temperatures limit its use as a porous electrode or current collector in solid oxide fuel cell (SOFC) configurations. Its relatively low melting temperature (962 degrees C) leads to accelerated densification of silver at operating temperatures of intermediate temperature SOFCs (550 degrees C-800 degrees C). In previous studies, powder based silver composites demonstrated stable microstructures with desirable porosity and electrical conductivity during long-term testing. Although the characterized features of the silver based composites allowed their use as efficient and stable cathode current collectors, they demonstrated limited electrochemical performance as a cathode layer. In this study, nanostructured coatings of various perovskite based cathode materials (lanthanum-strontium manganite (LSM), lanthanum-strontium ferrite (LSF), lanthanum-strontium cobalt-ferrite (LSCF)) were deposited into porous silver composites by infiltration of polymeric precursors to enhance their electrode efficiencies. As a result, novel metal-matrix perovskite nanocomposites were obtained. The properties of the Ag based nanocomposites allowed their use as a combined cathode and current collector layer with significantly improved electrochemical performance and long term stability at 800 degrees C in air. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.013211jes] All rights reserved.