Organic, hybrid and polymeric materials for energy
Coordinator: Dr. Matthieu Becuwe
The current energy context encourages research and development of new electrode materials that are more and more efficient while having a lower environmental and ecological impact as well as easier recycling. The contribution of organic chemistry in this area has been booming for the past ten years, particularly following work on eco-designed organic batteries. Our group focuses its activity on organic batteries (Li-ion and anionic) both in terms of the design of new high-performance electrode materials (materials and electrodes) and for the understanding of the mechanisms of electrochemical reactivity in the solid state. . The MOHPE group is also interested in the development of organic compounds in the broad sense, with an increasingly predominant activity on polymers and organic-inorganic hybrid materials to design new ionic conductors and more efficient storage materials.
New organic electrode materials for organic batteries (Dr M. Becuwe)
The field of organic batteries and organic electrode materials is expanding rapidly. In this context, our research activities focus on several aspects related to this type of compounds such as the synthesis of electroactive compounds, the assembly / organization of these molecules within a solid and the study of the electrochemical properties of materials which resulting. Initially, our research activities are oriented towards the precise study of molecular parameters (electroactive function, stabilizing fragment, etc.) and their influences on the electrochemical response (activity potential, reversibility, kinetics) for both the positive electrode (patterns quinonics, phenothiazine,…) than negative (lithium carboxylate). This methodology made it possible in particular to design organic electrode materials with modular properties, thus opening the way to high power organic batteries with extended output potential. More recently, our work in the field has opened up to the exploration of new families of electroactive compounds (phenothiazines for example) and to the understanding of the mechanisms involved during electrochemical reactions in the solid state, with the aim of arriving at the medium to long term to high performance all-organic prototype design.
Modeling of molecular and organized organic systems (Dr C. Frayret)
In partnership with experimental approaches, our simulation research is dedicated to the application of computer modeling to support in particular the selection of new functionalized organic electrode materials and to propose innovative designs of original and efficient systems at the molecular scale. Prior to any experimentation, the study of properties extended to a sampling of different structures of molecules or complexes by applying first principle calculations provides access to the identification of optimized molecular architectures, to knowledge of the sites of preferential intercalation, as well as the rationalization of structure-property relationships. One of the objectives of our work is thus to restrict the field of compounds to be targeted for experimental tests and to disentangle the relative incidence of distinct effects. The analysis of the precise characteristics of the electronic structure plays a key role here by providing an unprecedented and quantitative means of accessing an informed prediction approach for the engineering of new classes of materials. In addition to the exploration of data linked to different sets of systems, quantum mechanical calculations also offer, for the materials synthesized, the opportunity to participate in the characterization either from a structural point of view or from a spectroscopic point of view. The power of our approaches lies in the atomic resolution allowing a complementary understanding of the mechanisms compared to certain experimental techniques.
Development of electrolytes and polymer binders for Li-ion batteries (Dr J.-P. Bonnet / Dr M. Becuwe)
At the crossroads of the different laboratory themes, polymer materials are increasingly predominant compounds that can provide innovative solutions for ionic conduction (polyelectrolytes) or to contain volume variations and / or provide flexibility to the electrodes. As such, we are developing new polymerizable ionic monomers with a highly delocalized structure, architectured polymers for ion conduction and new polymer binders for negative and positive electrodes, in particular by upgrading compounds derived from biomass.
Hybrid organic-inorganic systems (Dr M. Becuwe)
The versatility of organic chemistry also offers many possibilities for improving the performance of materials (conductivity, energy and power density) via a hybrid organic / inorganic approach. This sub-theme is particularly aimed at developing new hybrid materials (according to several approaches) that can be used as electrolyte for the conduction of ions or as electrode materials for batteries and supercapacitors. A first option consists in creating a strong bond, of covalent or coordinative type, between an organic compound and an inorganic material. This has been exploited in particular for the design of new hybrid electrolytes without solvent based on ionic liquids immobilized on nanomaterials, resulting in conductivities of the order of 10-4-10-5 S.cm-1. Another possibility, which involves weaker bonds (VdW, π-stacking), has also been developed specifically for improving the storage capacities of carbonaceous materials for pseudo-capacitive storage. Carried out within the framework of a collaboration with the group of Prof. Yury Gogotsi (Drexel university, Philadelphia), the incorporation of electroactive organic compounds (quinone, phenothiazine, viologens, etc.) in large quantities within carbonaceous materials drastically improves the energy density of the electrode compared to unmodified materials.