Experimental study on the alleviation of thermal runaway propagation from an overcharged lithium-ion battery module using different thermal insulation layers

An efficient and safe thermal insulation structure design is critical in battery thermal management systems to prevent thermal runaway propagation. In this paper, using a common real-life overcharge as a trigger for battery runaway, we investigate the runaway response of the battery module without thermal insulation and with various thermal insulation materials. The experimental results indicate that the thermal insulation has the effect of stopping the thermal spread of the battery module and reducing the maximum temperature. By comparing the temperature change of the batteries, it is discovered that the fiber-based material has a temperature drop efficiency of 71.83%, while the aerogel materials are at least 13% more efficient in temperature reduction than fibrous materials. Meanwhile, it is demonstrated that by examining the capacity characteristics of the damaged battery and the characteristics of the insulation material, the pre-oxidized silk aerogel has the best thermal spread suppression effect and the TG (thermogravimetric) variation withstood high temperatures of up to 746 °C. SEM (scanning electron microscope) morphology for different insulation materials before and after combustion show that pre-oxidized silk aerogel maintains a strong thermal insulation capacity in the thermal spreading. It is expected to have a guidance for the design of thermal insulation in lithium-ion battery modules.