Description du sujet de thèse

The production and storage of energy are major challenges to ensure the energy transition. High energy density, cost-effective, and long-lasting batteries need to be developed to enable the widespread adoption of decarbonized energy and electrified transport. Currently, lithium-ion (Li-ion) batteries are predominantly used in portable electronics and electric vehicles. However, this battery technology is not adequate because the energy density should be increased by at least a factor of two to meet market needs. Additionally, the presence of a flammable liquid electrolyte poses a significant safety risk. A solution is to replace it with a solid electrolyte, which would pave the way for the safe use of a negative electrode made of lithium metal. The latter is the ideal candidate due to its high specific capacity but may require protection to make it compatible with the electrolyte.

In this context, the thesis project proposes to study and optimize lithium-sulfur batteries with a negative lithium electrode featuring an inorganic protective layer through a comprehensive set of electrochemical and physicochemical measurements. This project is part of a European research project, Horizon Europe, composed of 11 partners across 10 countries, which will officially start in May/June 2025. The various partners will provide the LEPMI laboratory with study materials (Li, protected Li, solid electrolytes, sulfur materials, etc.). The first part of the project, which will take place at the LEPMI laboratory, will focus on understanding the interface between lithium and the electrolyte, including the analysis of lithium electrodeposits (dendrites) through electrochemical measurements and X-ray imaging. A second part of the project will involve close collaboration (joint supervision) with the POLYMAT polymer research center in the Spanish Basque Country to optimize solid electrolytes by studying ionic conduction mechanisms. Finally, complete battery assemblies will be assembled, cycled, and then disassembled to study their recycling possibilities.

Contexte de travail

The LEPMI (Laboratory of Electrochemistry and Physicochemistry of Materials and Interfaces) is a joint research unit (UMR 5279) composed of researchers from the Centre National de la Recherche Scientifique (CNRS), the Université Grenoble Alpes (UGA), the Institut National Polytechnique de Grenoble (Grenoble-INP), and the Université Savoie Mont Blanc (USMB). The main research activities of LEPMI focus on the development, physical and electrochemical characterization of functional materials (polymers, salts, ionic liquids, catalysts, ceramics) for energy systems (batteries, fuel cells). The recruited person will primarily work within the Materials, Interfaces, and Electrochemistry (MIEL) team located on the Grenoble campus in Saint Martin d'Hères. The team focuses on the design and physicochemical and electrochemical characterization of polymers, salts, ionic liquids, ionomers, and electrolytes dedicated to energy storage and conversion (batteries: lithium-polymer, lithium-ion, lithium-sulfur, Mg, Na; protonic and alkaline polymer membrane fuel cells). Additionally, the team has extensive activity in operando and in-situ studies using coupled techniques: Electrochemistry/Raman, Electrochemistry/NMR, and other synchrotron techniques. The MIEL team consists of 19 permanent members, 15 PhD students per year, 4 postdocs per year, and 6 master's students per year. Part of the work will be conducted in collaboration with the Interfacial Electrochemistry and Processes (EIP) team to study aspects of material recycling. Finally, stays at POLYMAT in Spain as part of a joint supervision are planned to optimize the transport properties of electrolytes.

Contraintes et risques

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Informations complémentaires

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