The CEA-Grenoble has a strong research activity in the field of fuel cell that is one of the most promising zero emission power sources for automotive or stationary applications. The core of proton exchange membrane fuel cell (PEMFC), called MEA for “”membrane/electrode assembly “”, consists of two electrodes assembled on a membrane (ionomer) proton conducting. The electrodes exhibit a complex porous nanostructure consisting of carbon black supporting Pt nanoparticles and using an ionomer as the binder and electrolyte. To increase the performance and the life time of PEMFC, research is still needed to optimize the structure of the MEAs. Although the ionomer plays a crucial role as it ensures ionic conduction paths through the electrode, little is known about its distribution inside the electrode.

Recently, electron microscopy techniques developed on the Nanocharacterization Platform (PFNC) of Minatec allowed for the first time to image in 3D the morphology of the ionomer thin layer surrounding the carbon particles. Moreover, by chemical mapping it is now possible to determine the homogeneity of its distribution within the electrode. These analyzes open large perspectives on a better understanding of the ionomer distribution phenomena during electrode process and thus enable better control of its distribution within the electrode.

The aim of this thesis will be to analyze, using these advanced electron microscopy techniques, the distribution inside the electrode of different types of ionomer or of ionomer obtained by various manufacturing processes in order to optimize PEMFC performance. These analyzes will be carried out in parallel to electrochemical measurements that will characterize electrode performances. In a second time, as the stability or degradation of the ionomer in the electrodes during fuel cell operation is currently not known, similar analyzes will be conducted on aged electrodes.

This topic has great interest both from an academic point of view (understanding distribution of the ionomer and its evolution during operation of the fuel cell) and from an industrial point of view (development and optimization of ionomer or electrode manufacturing processes to increase their performance and life time).

This position is open until it is filled.

Department: Département de l’Electricité et de l’Hydrogène pour les Transports (LITEN)
Start Date: 01-10-2015
ECA Code: SL-DRT-15-0534
Contact: laure.guetaz<στο>cea.fr