Mitigating thermal runaway propagation in high specific energy lithium-ion battery modules through nanofiber aerogel composite material

Thermal runaway and its propagation within lithium-ion battery systems pose significant challenges to widespread adoption in electric vehicles and energy storage systems. Deploying a thermal barrier between adjacent batteries is a common and effective strategy to prevent thermal propagation. This experimental study evaluates the inhibitory effect of nanofiber aerogel on thermal propagation within high-energy-density lithium-ion battery modules. The results indicate that increasing the thickness of nanofiber aerogel prolongs the average time interval between thermal runaway propagation events between adjacent batteries and increases their peak temperature difference, while the maximum surface temperature of each battery exhibits an overall downward trend. Specifically, compared to no nanofiber aerogel, a 0.5 mm nanofiber aerogel extends the average propagation time by 2 times, and a 1.0 mm nanofiber aerogel successfully prevents thermal propagation from the third to the fourth battery, with an average time extension of nearly 6 times. Furthermore, it is found that thermal runaway propagation can be effectively prevented when the aerogel thickness exceeds 2.0 mm. The microstructure of both fresh and damaged nanofiber aerogels was examined using Scanning Electron Microscopy to validate and analyze their robust durability. This study provides valuable insights for designing safer high-energy-density battery systems.