IDEA-MAT

The IDEA-MAT project ‘Ion Diffusion and Exchange for the Design of Advanced Energy MATerials’ aims at directing the research of new Mixed Ionic Electronic Conductors materials with enhanced transport properties, for use in Solid Oxide Cells to provide society with a clean energy technology. While empirical route has been the main approach for finding new materials, we propose here to combine both experimental and theoretical studies in order to identify important features to direct the design of efficient electrode materials. Whereas most of research programmes deal with Solid Oxide Cells with an emphasis on the elaboration of systems and their durability, here, we propose a fundamental approach which could considerably impact the target application and the scientific community. By combining and developing ionic diffusion techniques, neutron diffraction and total scattering with structural modelling, we aim at identifying key parameters in the oxide ion and proton diffusion in order to propose some strategy for designing new electrode materials with enhanced properties. In parallel to the development of robust tools for the determination of transport parameters in electrode materials, novel compositions of layered oxides will be explored with emphasis on proton diffusion, a topic which has been scarcely studied. The project is a new one and will rely on a unique consortium with complementary skills:- Partner 1 – UCCS (Unité de Catalyse et de Chimie du Solide, Lille, team: Materials for Energy): coordination of the project, isotope exchange, extreme surface composition analysis by Low Energy Ion Scattering, thin film preparation, in situ X-ray diffraction under controlled atmosphere; - Partner 2 – SCR (Sciences Chimiques de Rennes, team “Chimie du Solide et Matériaux”): Materials synthesis, in situ neutron diffraction under controlled atmosphere at high temperature and use of the MEM and PDF to evidence oxygen and possibly proton diffusion pathways; - Partner 3 – SPMS (Laboratoire Structures, Propriétés et Modélisation des Solides, Ecole Centrale Paris) : oxygen content, electrical conductivity relaxation, diffusion mechanisms through Molecular Dynamics; - Partner 4 - CEA (Group of Condensed Matter Physics, CEA-DAM-IdF): Ab initio modelling of oxygen/proton diffusion/exchange. Coupling of 18O/16O isotope exchange (UCCS), relaxation techniques (SPMS), accurate surface (UCCS) and bulk (SCR) structural characterization and modelling (CEA), will allow a description of the oxygen transport from the macroscopic scale to the atomic one. Since Proton Ceramic Fuel Cell also appears as a promising technology, these techniques will be extended to the characterisation of proton diffusion in PCFC cathodes. We will focus here on layered oxide materials, which have shown to be among the most promising since the double functionality of electron/ion conduction might be tuned through an adequate control of the layers composition. Namely, 3 types of compounds will be studied 1) Ca3Co4O9 evidenced as a promising SOFC cathode by UCCS, 2) Double perovskites LnBaCo2O5+? and Ruddlesden-Popper (RP) with n = 1 Re2-xSrxCoO4+? cobaltites as potential PCFC cathodes whose proton diffusion has been scarcely studied, 3) Ruddlesden-Popper manganites (Ln,Sr)n+1(Mn1-xCrx)nO3n+1-d (n = 1, 2), possibly doped with chromium, as novel SOFC anode materials.