Incorporation of aerogel and encapsulating phase change material in thermal runaway propagation inhibition and interval optimization for lithium-ion battery

Thermal runaway propagation (TRP) always causes severe hazards with the flame and poisonous gas vented by lithium-ion batteries (LIBs). Phase change materials (PCMs), particularly organic ones, are flammable and can exacerbate TRP in LIBs, requiring a design to enhance the flame retardancy of PCMs. To mitigate fire risks during TRP and inhibit its spread by the ability of PCMs to absorb and dissipate heat, the flame-retardant PCMs (FRPCMs) are synthesized and encapsulated with graphene films to form encapsulated flame-retardant PCMs (E-FRPCMs). The E-FRPCM is designed to enhance heat dissipation through structural encapsulation, improving thermal conductivity and flame retardancy while preventing leakage under extreme thermal loads. The E-FRPCMs of varying thicknesses are coupled with aerogel felt (AEGF) to suppress TRP in neighboring cells of battery module. The variations in voltage, temperature, mass, and heat flux are monitored throughout the TRP process. The mechanism of TRP inhibition by these materials is analyzed, and the experimental results are compared. The findings show that, in terms of overall TRP suppression, the encapsulated sandwich (E-Sandwich) structure significantly reduces battery surface temperature and effectively inhibits TRP. Among the tested structures, the E-Sandwich demonstrates the best TRP suppression performance, highlighting its potential for optimizing battery module interval.