Modeling cell venting and gas-phase reactions in 18650 lithium ion batteries during thermal runaway

A coupled conjugate heat transfer and CFD model for the thermal runaway evolution and jet fire of 18650 lithium-ion battery under thermal abuse

“…When the internal pressure of the cell increases to a critical pressure of Pcir = 1.9 MPa for the currently considered 18650 cell [40], the vent valve opens to release the generated gases and aerosols of electrolyte vapor. Due to the breakdown of the VLE condition inside the cell, the previous equations of state under VLE condition is no longer valid and several ODEs can be written to simulate the dynamic change of the pressure with time inside the cell.…”

“…Thus, the effect of electrolyte vapor combustion on the heat release of jet fire is not considered. In this model, the reduced kinetics of hydrocarbon oxidation is modelled by two-step reaction mechanism while the burning of hydrogen is assumed as one-step reaction [40]:…”

“…Although such modeling efforts have successfully described the interconnection between the thermal abuse reactions, pressure build-up and venting characteristics, the subsequent flow field following venting and the evolution of the resulting jet fire were not addressed. Kim et al [40] developed an alternative approach by considering the random porous media rather than classical solid to model the LIBs. They used the change of the porous media scaling factor at the bottom of the vent to link cell interior and exterior.…”

Experimental analysis on comprehensive combustion performances of vehicle-level thermal runaway

“…Chen et al [18] introduced the experiments on different capacity of cylinder battery, and the results indicate that it would be a good practice to store and transport lithium-ion batteries at zero stage of charge. Kim et al [19] performed experiments on battery fire with different state of charge, and cells with higher SOCs will lead to more heat and gas generation during the vent opening, and consequently result in higher internal pressures which increase the risk of side-wall breaching. Zhang et al [20] introduced the influence of different heating methods for triggering thermal runaway of batteries, and analyzed the dramatical performances on cylinder batteries.…”

Battery Hazards for Large Energy Storage Systems

“…Several lumped − and multidimensional − models for single Li-ion cells have been developed to capture various underlying physical phenomena occurring during thermal runaway, including heat and mass transfer, gas generation, exothermic chemical reactions, electrolyte evaporation, venting of flammable gases, and combustion. In addition, thermal runaway models have been extended to battery packs and modules to characterize cell-to-cell propagation.…”