“Optimisation of a cerium oxide coating in an ORCEPAC fuel cell”
Partners: UTBM, EPFL, Dephis, Fiaxell SARL
Duration: 2 years, 04/2016 – 04/2018
To obtain efficient Solid Oxide Fuel Cells (SOFC), it is necessary to use electrodes containing cobalt (LSC, LSCF) on the cathode side; zirconium oxide (zirconia) based materials for the electrolyte; and a Ni/8YSZ cermet for the anode. However, the zirconia and cobalt-based electrodes react together at the cell’s operating temperature (800°C) to form resistant composites. It is therefore necessary to insert a protective cerium oxide (ceria) ceramic layer between the cathode and the zirconia electrolyte. Ceria-based composites provide good thermomechanical and chemical compatibility between the electrolyte and the cathode. Within the framework of a previous spontaneous collaboration between Fiaxell and the University of Technology of Belfort-Montbéliard (UTBM), cells of reduced size were covered with thin films of ceria by physical vapour deposition (PVD). The initial results of these samples showed a significant increase in electrochemical performance, and gave rise to the publication of various papers.
The aim of this project is to highlight the industrial feasibility of PVD for the fabrication of protective ceria-based thin films. In order to achieve this, it will be necessary to optimise the depositions and characterise them electrochemically and microstructurally. This will allow for obtaining the densest and thinnest films possible. The consortium carrying out this study is made up of two companies, Fiaxell (Switzerland) and Dephis (France), plus two academic partners, EPFL (Switzerland) and UTBM (France). Fiaxell will produce the base solid oxide fuel cells with a zirconia electrolyte. Dephis, in collaboration with the University of Technology of Belfort-Montbéliard (UTBM), will develop the method for creating the protective layer using PVD on an industrial scale, and its characterisation. Meanwhile, Fiaxell will continue to optimise ceria deposition using silk-screen printing with a nanoparticle-based ink followed by sintering (post-sintered ceria). This technique will serve as a technical and commercial standard during the project. Fiaxell’s academic partner, École polytechnique fédérale de Lausanne (EPFL), will be responsible for the microstructural characterisation (SEM) and electrochemical characterisation (impedance spectroscopy) of each element of the functional structure.
This project is carried out within the framework of the European cooperation programme INTERREG VA between France and Switzerland. It has received financial support from the EU through the European Regional Development Fund (ERDF) (EUR 139,176) and the Swiss Confederation (CHF 134,173).