Designing Micro-SOFC Devices through the Sol-gel Process?

Guillaume Muller (1) , Armelle Ringuedé (2) , Gianguido Baldinozzi (3, 4) , Clément Sanchez (1) , Christel Laberty-Robert (1)

1 Chaire Chimie des matériaux hybrides
2 LECIME - Laboratoire d'Electrochimie, Chimie des Interfaces et Modélisation pour l'Energie (LECIME - UMR 7575)
3 SPMS - Laboratoire Structures, Propriétés et Modélisation des solides
4 LA2M - Laboratoire d'Analyse Microstructurale des Matériaux

This presentation reports on a facile, cost effective and versatile method to fabricate nanostructured, mesoporous NiO-Gd-CeO2 (GDC) Gd-CeO2, La1-xSrxFe1-yCoyO3+delta and GDC/LSCF films. These films were synthesized through the "sol-gel method" combined with the dip-coating approach. Compared to spray-pyrolysis, APCVD or ALD methods, the proposed method avoids the use of expensive equipment and metal-organic precursors. In addition, we focussed on relatively low temperature processes that allow retaining a well-organized nanostructure within the material. Different techniques were used to characterize the films: FE-SEM, XRD, XPS, HR-TEM. Additionally, thermal or porosimetry Ellipsometry were also performed to define the heat treatment that allows synthesizing films with controlled porosity and particle size and to characterize the porous network, respectively. Using X-ray diffraction techniques coupled with a modelling approach, we have studied the formation of particle into these mesoporous films and we have shown that particle growth is governed by the surface curvature within the films. Based on these results, a discussion on the stability of the film has been proposed. Electrochemical characterization has been performed to characterize our films under various conditions of temperature and atmosphere (air and 5%H2/N2). For NiO/GDC mesoporous films, we have developed an "in-situ" technique based on impedance spectroscopy to understand the mechanism of reduction of NiO to Ni into the mesoporous Gd-CeO2 films. These studies allow us designing the films with the adequate microstructure and composition. In parallel, we have extended this impedance based approach to the characterization of the cathode, GDC/LSCF. This study permits to propose a heat-treatment that conduces to the formation of highly conductive GDC/LSCF. Finally, these films were used to synthesize a micro-SOFC and performances will be discussed as function of the architecture of the micro-SOFC device.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Guillaume Muller, Armelle Ringuedé, Gianguido Baldinozzi, Clément Sanchez, Christel Laberty-Robert. Designing Micro-SOFC Devices through the Sol-gel Process?. Symposium I – Functional Materials for Solid Oxide Fuel Cells , Nov 2012, Boston, United States. ⟨hal-00761581⟩