Experimental and Kinetic Modeling Study of Gas Generation During Calendar and Cycling Aging of Lithium-Ion Batteries

Lithium-ion batteries, although highly efficient, can pose risks not only under abusive conditions but also within normal conditions of use set by the manufacturer. The risks are not limited to everyday use, and also concern the industrial sector (storage, construction, reconditioning, waste treatment, recycling). Indeed, a 25% increase in incidents related to lithium-ion batteries at recycling centers in UK and US has been observed in recent years. A 71% increase in battery fires since 2022 is also reported. Finally, chemical risks, through the inhalation of toxic gases in the event of a breach of containment, have been observed. These emissions consist of volatile organic compounds, as well as toxic gases such as hydrogen fluoride, which is of particular concern due to its toxicity and corrosive potential. They can occur even when the battery is under normal storage and operating conditions which induce calendar and cycling aging.
To address these issues and mitigate the risks, a good understanding of the formation mechanisms of toxic gases and accurate predictions on their evolution are, therefore, of imperative necessity and critical significance. In this thesis, we aim to develop a chemical kinetic model, focusing on the evolution of electrolyte in both liquid and gas phases, to predict the temporal evolution of the gas composition inside commonly used batteries (e.g., NMC and LFP chemistry). The model will consider different degradation mechanisms identified in the literature, particularly those related to temperature variations, charge/discharge conditions, and material aging. Experiments with analysis on the chemical composition will be conducted for model validation. This work will contribute to a better anticipation of battery behaviors and ultimately to the implementation of appropriate preventive measures. The PhD candidate will acquire solid experience in lithium-ion batteries, thermodynamics, chemical kinetics, and multi-physics modeling.
 

Keywords: Lithium-Ion Battery, Electrolyte, Aging, Gas Generation, Safety, Hazard, Occupational Health, Chemical Kinetics, Kinetic Modeling

• Academic supervisor    Prof. SIRJEAN Baptiste, Laboratoire Réactions et Génie des Procédés (LRGP), CNRS, Université de Lorraine
• Doctoral School    ED 608 - SIMPPÉ - Sciences et Ingénierie des Molécules, des Produits, des Procédés et de l'Énergie (website)
• IFPEN supervisors    Dr. XU Boyang, Research Engineer & Dr. BOLMONT Mickael, Research Engineer
• INRS supervisors    Dr. MONNIER Hubert, Responsable d'Etudes & Dr. VAUFLEURY Maxime, Responsable d'Etudes
• PhD location    IFP Energies nouvelles, Rueil-Malmaison, France 
• Duration and start date    3 years, starting from 4th trimester 2026
• Employer    INRS, Vandoeuvre, France. Salary: 2726.64 €/month gross (as of Jan. 2025)
• Academic requirements    University Master degree (or equivalent) in chemical engineering, physical chemistry, electrochemistry, or materials engineering
• Language requirements    Fluency in English. Fluency in French is a plus.
• Other requirements    Modeling. Experimental skills. Python. Knowledge in chemical kinetics is a plus.

To apply, please send your CV and cover letter to the supervisors below.