Experimentation and numerical simulation of lithium battery thermal runaway
12-month fixed-term contract
CEA Saclay - F-91191 Gif-sur-Yvette, with regular travels to Grenoble for experimental testing.
The work will be organised into three main content areas:
- A first part will enable to understand, master and model the different phases of the scenario, especially the combustion phase, based on experimental tests dedicated to the characterization of these phases. Two types of tests will be realised:
- Abusive tests on 18650 batteries , with monitoring of temperature, pressure increase, gas nature and flow-rate, cell released thermal energies, and combustion (oxygen level, flame speed),
- Combustion and fluid-structure interaction tests in a shock tube to determine the explosive gas mixtures characteristics and validate the behaviour models implemented in the calculation codes.
- New experiments might be proposed to investigate particular issues, evaluate some parameters influence, or complete validation data, with the aim of a best understanding and control of the phenomena and their modelling.
- The second part will be dedicated to the development of a numerical model representative of phenomena identified in the first part, on the basis of CEA numerical tools, in particular EUROPLEXUS  and CAST3M . At first, the fluid structure interaction will not be considered. If necessary, new models or functionalities will be adapted, improved or developed, with verification and validation based on experimental results. A roadmap for tools evolution in the medium and long term will be proposed.
- According to the work progress, a third part will consist in introducing the fluid structure interaction in the modelling. It is a question of taking into account the potential deformation of the battery or pack envelop, due to pressure increase generated by the thermal runaway (gas release + combustion). Coupling methods available in EUROPLEXUS (ALE, immersed boundaries) could be investigated in particular.
The results of this post-doctorate should enable to evaluate the capabilities of the current tools and numerical methods to simulate the Li battery thermal runaway phenomenon, and orientate the development of numerical methods and calculation codes for the coming years in order to improve their predictivity on this new problem. Publications will be proposed in targeted international journals (Journal of Power Sources, or International Journal for Numerical Methods in Engineering …), as well as presentations at conferences.