Reliability and durability are key considerations to successfully deploy Proton Exchange Membrane Fuel Cells (PEMFCs). Since the link between materials defects and performances at the scales of the Membrane Electrode Assembly (MEA) and the stack is now well documented, LOCALI shall provide information about the propagation of these defects to other materials or to other locations in the stack. LOCALI aims to improve the existing systems and will ultimately provide effective tools to control their mass-production, the quality of the stacks and their diagnosis for on-site maintenance (stationary) or for on-board (transportation) applications. To these goals, the study focuses on three main axes, developed for PEMFCs (but which can easily be implemented for E-PEM). Firstly, LOCALI will develop instrumentation dedicated to local current density measurement and local electrochemical impedance spectroscopy: well-instrumented segmented cells and magnetic fields measurement are the core competences to these goals. The second challenge of LOCALI is, by using tailored defective MEAs or thanks to specific operating conditions (flooding, reagent exhaustion, ...) to characterize how local and overall performances of the MEA are affected, and to identify the signatures of the various anomalies. Our target is to identify the source of the heterogeneities as well as to locate degraded areas inside a stack. Finally, LOCALI will enable to track, during ageing, how the initial and controlled defects do propagate upon operation. A particular attention will be paid on two points: (i) does a defect in the one material of the MEA (e.g. a hole in the PEM) influence the local degradation of its neighboring materials (e.g. the catalyst layer); (ii) does the defect propagate spatially, and if so, does it happen only at the MEA scale (e.g. from the inlet to the outlet regions) or at the stack scale (i.e. from the defective cell to its neighboring ones).

The MOCA project is dedicated to the study of thin films single crystals from the perovskite family obtained on Silicon substrate by epitaxial routes. The materials developed will be Pb(Zr,Ti)O3 (PZT) with Zr/Ti=52/48 and (Ba,Sr)TiO3 (BST) with Ba/Sr=70/30. Three different deposition techniques will be performed: Molecular Beam Epitaxy (MBE), sol gel and Pulsed Laser Deposition (PLD). The targeted proofs of concept are three fold: acoustic resonators, high-K capacitors and piezoelectric actuators. The final aim of MOCA is to provide a clear status on the superiority of the epitaxial single crystal thin films compared to their polycrystalline counterpart. Four partners will be involved in MOCA. CEA LETI Minatec will be the leader of the project and will process the sol gel layers (PZT and BST) deposited on SrTiO3 (STO) buffered layers, which is mandatory to obtain single crystals on Si. LETI will also realise several proof of concepts devices: resonators with FEMTO, capacitors and piezoelectric or electrostrictive actuators. He will characterize these devices. INL will bring his expertise on MBE to the consortium. He will prepare the template Si wafers with the STO layer and will work specifically on this template layer. He will also prepare BST active layers in order to compare their properties to the one obtained with the other techniques. A demonstrator will be done by the partners (actuators or/and resonators). INL will provide the template layers to the partners. SPMS will work on the PLD route as it is also a recognized way to obtain single crystals as thin films. He will also help the consortium to characterize the structural behaviour of the layers deposited. FEMTO will realize resonators and characterize them. The consortium is very complementary on this dedicated topic of perovskite single crystal on Si. Finally, ST Tours, industrial with a long experience of integrating PZT capacitors with Si, will elaborate specifications and will test the capacitors based on single crystals perovskite in the framework of the MOCA project. The partners have already several common projects and developed the know-how to work together for a long time.