Simulation of Li-ion battery electrolyte vapour dispersion in an enclosed and quiescent environment: an experimental and computational fluid dynamics approach

The leakage of electrolyte from a Li-ion battery cell can generate a dangerous atmosphere in enclosed environments due to the high volatility, flammability and toxicity of common electrolyte solvents like dimethyl carbonate (DMC) and diethyl carbonate (DEC). The use of early warning and detection systems is essential to detect the leakage, even after the solvents have fully evaporated, to limit human exposure. To aid in their design, this work introduces a novel computational fluid dynamics (CFD) dispersion-evaporation coupled model, which was validated by measuring the dispersion of electrolyte vapours in an enclosed 1 m3 box with no induced flow. The Large Eddy Simulation (LES-CFD) dispersion-evaporation model produced good results, as it demonstrated good agreement with experimental measurements at 15 and 30 cm above the source for both DMC and DEC. Experimental and simulated results also show a two-fold dispersion mechanism, a convection-based effect dependent on the density of the heavy vapour cloud gasses and surrounding environment, and a diffusion-based effect, which becomes dominant once the ambient density has homogenised across the domain.