The objective of the thesis is to characterize the ignition of vent gases resulting from the thermal runaway of lithium-ion cells. During the venting phase, the cell emits electrolyte vapours that mix with the air, and then during thermal runaway, a hot jet of gases and particles is formed that can enrich the mixture and ignite it. The underlying scientific questions concern the evolution of the fundamental characteristics of combustion (flame velocity and auto-ignition delay) with temperature, pressure and composition, ignition mechanisms and the impact of the environment on the preponderance of one of the mechanisms.
To answer this question, we will first use an approach based on the identification of a reaction kinetic model using existing results in the literature and complementary tests to be performed in the thesis at the cell level. Then, we will experimentally characterize the conditions of ignition of mixtures by a hot jet of gas and particles in a shock tube coupled to a combustion chamber. Finally, the mapping obtained on the basis of the knowledge acquired on the mechanisms and conditions of inflammation will be reinterpreted.