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PhD subjects

2 sujets INAC

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• Soft matter and complex fluids

A new class of polymer electrolytes for lithium ion batteries: multi scale structure and transport properties

SL-DSM-14-0413

Research field : Soft matter and complex fluids

Location :

Structures et Propriétés d'Architectures Moléculaires (SPrAM)

Groupe Polymères Conducteurs Ioniques (PCI)

Grenoble

Contact person :

Hakima MENDIL-JAKANI

CEA
DSM/INAC

Starting date : 01-10-2014

Contact person :

Hakima MENDIL-JAKANI

CEA - DSM/INAC

04 38 78 91 71

Thesis supervisor :

Sandrine LYONNARD

CEA - DSM/INAC

04 38 78 92 86

Lithium-ion batteries are efficient electrochemical devices for storing electrical energy, produced for instance by intermittent sources (wind, solar). They are also attracting a growing interest due to their use in on-board automotive and portable applications. Nowadays, the improvement of energy density and safety aspects is a major issue. However, the development of this technology is limited by short -circuiting hazards and flammability of standard liquid electrolytes. The CEA-LITEN recently developed a new material based on free solvent lithium ion conducting polymer. High performances (safety, conductivity) were obtained when such electrolytes have a crystalline structure in the solid state. The thesis aims at understanding the microscopic properties of these promising materials and their impact on the functional properties, for the design of high performance batteries. A systematic study of the structure / transport relationship will be carried out by combining sophisticated experimental tools: cutting-edge scattering experiments on Large Scale Facilities, AFM, impedance spectroscopy and NMR. The impact of both chemical parameters and process will be evaluated to optimize the best electrolyte material. At the end, a prototype of a safer and efficient battery will be delivered. This basic research project t is therefore directly related to the technological development of new generation lithium-ion batteries and will benefit from the complementary expertise of the host laboratory CEA- INAC- SPrAM (multi- scale characterization of polymer electrolytes ) and his partner, CEA- LITEN (synthesis / test innovative materials).

Fuel cells : surfactant doped-membranes for boosting conductivity.

SL-DSM-14-0443

Research field : Soft matter and complex fluids

Location :

Structures et Propriétés d'Architectures Moléculaires (SPrAM)

Groupe Polymères Conducteurs Ioniques (PCI)

Grenoble

Contact person :

Patrice RANNOU

CNRS
DSM/INAC/SPrAM/LEMOH

Starting date : 01-10-2014

Contact person :

Patrice RANNOU

CNRS - DSM/INAC/SPrAM/LEMOH

0438782749

Thesis supervisor :

Sandrine LYONNARD

CEA - DSM/INAC

04 38 78 92 86

Fuel cells are promising alternative energy sources developed notably for on-board automotive and portable applications. A major issue for fuel cell industrialisation is the polymer membrane optimisation in terms of performances (conductivity, life-time, cost). The membrane is a complex nanostructured charged electrolyte insuring proton conduction and isolating the two electrodes. A fine understanding of the structure/transport/properties relationship is crucial for designing safer sustainable low-cost innovative electrolytes. We develop an approach based on the optimization of the benchmark Nafion membrane by incorporating surfactants We have shown that surfactant doping leads to a more nanostructured material with improved conductivity (gain by a factor 2 at least). Even more promising is the possibility to create oriented ionic channels inside cast hybrid membranes. The thesis aims at optimizing the doping (chemistry and process) in order to design high performance anisotropic membranes. This subject is clearly an experimental multi-disciplinary subject, starting from the synthesis of well-chosen surfactants, the hybrid membranes elaboration, the caracterisation of macroscopic properties (sorption, conductivity, mechanical and thermal), structure (Scattering techniques using wolrd-class Large Scale Facilities ESRF and ILL) and transport (Neutron scattering coupled to NMR). It is thus the opportunity to study a strategic and complex material in the field of new energies with a panoply of sophisticated cutting-edge techniques.

 

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