La[sub 0.6]Sr[sub 0.4]Co[sub 0.2]Fe[sub 0.8]O[sub 3−δ] Current Collectors via Ag Infiltration for Microtubular Solid Oxide Fuel Cells with Intermediate Temperature Operation

Nickel–cermet anode-supported microtubular solid oxide fuel cells (SOFCs) based on a (LSCF) cathode exhibit high power density at temperatures . Current collecting is a major obstacle toward the integration of these single cells in a cube-shaped module; such integration would finally lead to a higher volumetric power density. This study aims to develop and modify current collectors for high performance in compact high power cube-shaped SOFC modules. The feasibility of using porous LSCF that has been infiltrated by Ag as a current collector for high performance SOFC modules is investigated. The well-dispersed Ag particles enhance the electrical conductivity and increase the thermal expansion coefficient of LSCF. Based on the oxygen content measured by thermogravimetry and the crystal structure analyzed by synchrotron X-ray diffraction, it appears that the enhancements of thermal expansion and electrical conductivity are related to the formation of oxygen vacancies and the increased covalency of the (Co, Fe)–O bond in LSCF, respectively.