Development of supported LSM films in metal interconnector for application in solid oxide fuel cells (SOFC)

Abstract

This proposal focus on the synthesis and characterization of thin films based on La0.7Sr0.3MnO3 (LSM) deposited on metallic substrates based on commercial ferritic steels STS 444-17%Cr e STS 446-23%Cr (STS- stainless steel) used as interconnectors in Solid Oxide Fuel Cells (SOFC). Substitution of the usual ceramic interconnector based on LaCr03 by the metallic interconnector based on ferritic steel aims to decrease the overall cost of this type of device. The development of this work consists in the superficial treatment of the chosen metallic alloys (composition, roughness, adherence, etc); study and choice of the most suitable parameters for nanostructured LSM film depositíon; morphological and microstructural evaluation of the prepared materials; evaluation of the depositíon process in multistage layers; evaluation of the Cr-diffusion reaction (before and after the oxidation - 200 h under air- step) on the interface between the Fe-Cr alloy and the LSM coating, and the formation of (Cr,Mn)304 and Cr203 on the substrate surface; and the possible formation of SrO and MnOx species, originally enriched or segregated on the surface of LSM, mainly in the starting phase of the reaction by techniques like MEV, EDS and XRD. Electrochemical measurements using 2 probes and 4 leeds and impedance spectroscopy will be able to offer some information regarding porosity, reactivity and electric properties of the thin films. (AU)