Effect of composite phase change thermal insulation layer on thermal runaway propagation in lithium-ion battery modules

In the field of electric vehicles, the thermal runaway (TR) suppression of lithium-ion battery is still a challenge and battery thermal management systems (BTMs) is needed to enhance safety. Based on the experimental data of adiabatic TR of single cell, A model for suppressing TR propagation in lithium-ion batteries was established. Through a series of data analysis, the effect of nano ceramic fiber adsorbing four different phase change materials (PCMs)—saturated calcium chloride solution (SCCS), silica sol, tetraethyl phosphate (TEP) and tetraphenyl phosphate (TPP)—on TR propagation was studied. Compared to previous studies, through high adsorption efficiency and large latent heat, the heat insulation performance of the insulation layer was improved. Results demonstrate that insulation layer adsorbed with SCCS or silica sol successfully block TR propagation. Compared with adsorption of silica sol, SCCS (latent heat difference 25%) reduces the maximum surface temperature of adjacent cells from 151 °C to 137 °C (a relative decrease of 9.3%). Specifically, the self-generated heat of adjacent cell is reduced by 40%. These findings emphasize the key role of higher adsorption efficiency combined with larger phase change latent heat in suppressing TR propagation, and enhance safety and reliability.