Experimental and kinetic study on the explosion characteristics of lithium-ion battery vented gases

The thermal runaway and catastrophic failures of lithium-ion batteries that release combustible gases, which, when mixed with air, can lead to explosions and fires. In this paper, experiments were conducted to determine the laminar flame speed and explosion pressure of the battery vent gases (BVGs). The effects of CH ratios, defined as the ratio of C atoms and H atoms in mixtures, ranging from 0.2 to 0.8, and equivalence ratios (Phi), Phi ), varying from 0.8 to 1.8, on laminar flame speed and explosion pressure are investigated and confirmed. Furthermore, the laminar flame speed of various BVGs was simulated using three kinetic schemes. Results show that the simulated laminar flame speed using the Foundational Fuel Chemistry Model Version 1.0 (FFCM-1) matches well with the experimental data. The sensitivity analysis shows that reactions R1 (H + O2 2 O + OH) and R97 (CH3 3 + H (+M) +M) CH4(+M)) 4 ( +M)) are two dominant chain branching and chain termination reactions that affect the laminar flame speed. The rate-of-production analysis shows that the reactions R1 (H + O2 2 O + OH) and R4 (O + H2 2 H + OH) are the two main routes for the production of H, O, and OH radicals. The concentration of H, O, and OH radicals shows different development trends as the equivalence ratio and CH ratio change. However, the concentration of key radical pools, i.e., [H + O + OH], shares the same trend as the laminar flame speed and maximum explosion pressure. Results indicate that the concentration of [H + O + OH] controls the explosion characteristics of premixed BVG/air mixtures.