A study of premixed combustion of gas vented from failed Li-ion batteries

Abstract

As the world moves towards more clean and suitable energy sources such as wind and solar, there is an increasing demand for energy storage systems. Lithium-ion batteries (LIBs) are today the leading electrical energy storage system due to high energy density, high specific energy, and low maintenance requirement compared to other traditional batteries. However, the combination of flammable organic electrolytes and the release of oxygen at elevated temperatures in LIBs presents a potential hazard, with numerous fires and explosions reported in the last decades, where failing LIBs were the cause. This study focuses on the explosion hazards by experimentally and numerically studying the premixed combustion of various gas compositions vented from failing LIBs.

In this study, two experimental setups have been used, a 20-liter explosion sphere and a 1-meter explosion channel. In the 20-liter explosion sphere, the maximum explosion pressure, the maximum rate of explosion pressure rise, and the laminar burning velocity (LBV) have been determined for three electrolyte solvents and three Li-ion vent gas compositions. The results showed that the three electrolyte solvents had very similar explosion characteristics, which were also similar to the propane characteristics. Furthermore, the LBV for all gas compositions analyzed ranged from 0.3 m/s to 1.1 m/s, illustrating the influence of certain vented species and their concentrations on the LBV.

The experimental results obtained from the 1-meter explosion channel were used to evaluate model performance a computational fluid dynamic (CFD) method for simulating an explosion from gases vented from failing LIBs using only open-source software. Three different gas compositions and three different channel geometries have been experimentally and numerically studied. In addition, a code for generating the required CFD parameters for combustion, thermodynamic, and transport properties is presented. Finally, the CFD method gave an overall acceptable model performance when comparing the experimental and numerical temporal evolution of the pressure, maximum pressure, positive impulse, and spatial evolution of the flame front velocity.