Enhancing battery module safety with insulation material: Hollow glass microspheres incorporating aerogel of varying particle sizes

Thermal runaway propagation (TRP) in lithium-ion batteries (LIBs) poses a critical safety concern, hindering their widespread application. In this study, we present a novel thermal insulation material designed to effectively mitigate TRP in LIBs. The material comprises a mechanical support framework consisting of hollow glass microspheres (HGMs) and acrylic emulsion, filled with aerogel particles (APs). We systematically investigate the influence of HGMs and APs addition on the properties. The findings reveal a positive correlation between HGMs and mechanical properties, as well as APs and thermal insulation properties, at appropriate addition levels. The optimal insulation material exhibits exceptional compressive strength (1.42 MPa), achieves a UL-94 V-0 flame retardancy rating, and demonstrates high thermal insulation performance (44.3 mW & sdot;m- 1 & sdot;K- 1). Moreover, we explore the impact of strain on thermal insulation performance, observing a gradual increase in thermal resistance loss with higher strain. Notably, even at a strain of 70 %, the thermal conductivity experiences only a modest increase from 44.3 to 52 mW & sdot;m- 1 & sdot;K- 1. Additionally, we evaluate the effect of APs size on the material's properties, finding that decreasing particle size from 50 to 5 mu m leads to a reduction in mechanical properties (1.42 to 1.12 MPa) but an improvement in thermal insulation performance (44.3 to 39.7 mW & sdot;m- 1 & sdot;K- 1). Finally, we validate the practical efficacy of the insulation material in preventing TRP through the use of a 2 mm thickness. This study presents a promising approach to enhance the safety of LIBs by developing an efficient insulation material with outstanding properties.