PhD Thesis in mechanical and material engineering - Analysis of the mechanical behavior of a single...

Thesis description

The SEATBELT project aims to develop a solid-state lithium metal battery with in-situ hybrid electrolyte. Solid-state batteries are considered today as one of the most promising solutions to reach the energy density targets set by Europe, outperforming all current technologies for stationary and mobility applications. However, replacing the liquid electrolyte with a solid-state membrane poses new challenges. In an entirely solid-state architecture, the quality of the interfaces between the different materials of the cell plays a crucial role in its electrochemical performance, which also depends on the mechanical state of the different cell components. One of the challenges of this new generation of batteries is to increase their performance, while ensuring their electromechanical stability.

In this context, this thesis is based on a numerical and experimental analysis of the mechanical behavior of a single cell (or pouch cell) of a solid-state battery, which will be developed in the framework of the SEATBELT project. The development of a mechanical model, via a finite element analysis performed with the COMSOL software, will be carried out in the first place. This model will be based on the real geometry of a pouch cell, including its different layers and materials as well as different interface conditions (bonded, sliding or with a friction coefficient). The new materials developed in the SEATBELT project will be characterized and their properties will be implemented in the numerical model. Experimental measurements will be carried out in order to compare the experimental and predicted mechanical behaviors. In close collaboration with the laboratory 3SR, morphological characterizations by X-ray and neutron tomography will be performed on the pouch cell under mechanical stress. Particular attention will be paid to the degradation mechanisms occurring in the pouch cell during its solicitation, using in particular the measurements of the displacement and deformation fields. The last part of the study will be devoted to the implementation of coupled electromechanical measurements in order to analyze the influence of the generation of stresses or strains in the pouch cell on its performance. All the experimental and numerical results acquired in this study will allow to validate not only the choice of the materials developed for the new generation of batteries but also to propose an optimized assembly mode to reach the performances targeted in the SEATBELT project.

Working context

The LEPMI (Laboratory of Electrochemistry and Physical Chemistry of Materials and Interfaces) is a mixed unit (UMR 5279) composed of researchers from the National Center for Scientific Research (CNRS), the University of Grenoble Alpes (UGA), the National Polytechnic Institute of Grenoble (Grenoble-INP) and the University of Savoie Mont-Blanc (USMB). The main research activities of LEPMI are the elaboration, physical and electrochemical characterization, of functional materials (polymers, salts, ionic liquids, catalysts, ceramics) for energy systems (battery, fuel cell).

The person recruited will work in the GUIDE team (Genesis and use of sustainable interfaces for energy) located at the Savoie Technolac technology park in Le Bourget du Lac, which is made up of 25 people, including 10 PhD students/post-doctoral fellows/interns.

Candidate profile

Student with a master’s degree or equivalent in mechanical engineering or materials science. This thesis is intended for candidate with a strong interest in in mechanics of materials with good skills in finite element analysis. Knowledge of COMSOL software and experience in material characterization is a plus.

Additional details

Working place: Le Bourget-du-Lac (FRANCE)

Starting date: 1st February 2023

Salary: 2 135€ gross monthly

https://seatbelt-project.eu/

Procedure

To apply, send your application (CV with references + cover letter) to Christophe CARRAL ([email protected] )

Keywords: solid-state battery, numerical simulation, experimental characterization, finite element analysis