In recent years, Li-ion batteries have become the benchmark technology for the global battery market, supplanting the older Nickel-Cadmium and Alkaline technologies. Although slightly inferior to fossil fuels in terms of massic energy capacity, Li-ion batteries have a major advantage for the development of electric vehicles: their exceptional lifespan. It has recently been demonstrated that particular electric vehicle technologies can exceed one million km. Beyond the promising performance of ideal prototypes, the question of battery lifespan is linked to industrial, economic and environmental issues that are crucial to the ecological transition and energy sovereignty of our country.

One of the major challenges in developing these long-life batteries is to anticipate and control the various internal degradation phenomena that occur during actual use. Although most degradation phenomena have been identified in laboratory on common battery materials, the question of their kinetics in a battery pack in real use remains open, as does the prediction of the battery's state of health and end-of-life.

CEA's teams draw on a unique expertise combining experimental data and modeling to build a predictive physico-chemical model of Li-ion battery degradation. As part of this thesis, you will design and carry out basic characterization experiments on battery degradation mechanisms in the laboratory, using a wide range of advanced experimental techniques (electrochemical titration, impedance spectroscopy, operando gas measurements, DRX, etc.). Your work will also involve integrating your results into aging models, and studying the predictions and validation of these models.