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.
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.
The aerogel materials are at least 13% in temperature reduction than fibrous materials. The pre-oxidized silk aerogel have the best thermal spread suppression effect. An efficient and safe thermal insulation structure design is critical in battery thermal management systems to prevent thermal runaway propagation.
There was no significant deformation or melting before and after burning for pre-oxidized silk aerogel, so it maintained a strong thermal insulation capacity in the thermal spreading. The fiber structure of glass fiber aerogel became molten droplets and the spatial mechanism was destroyed after combustion. 4. Conclusions
However there is a lack of comparative experimental studies on the application of aerogel and nanofiber materials for thermal spread suppression in battery modules. Moreover, the majority of researchers studying the phenomenon of battery thermal runaway use external heating sources to trigger the runaway .
When the battery surface temperature exceeded 200 °C, the battery was highly susceptible to thermal runaway. The 3 C overcharge experiments with different thermal insulation materials indicated that the thermal insulation materials could block the heat transfer and control the second cell surface temperature to below 200 °C.