Preparation and characterization of fire-extinguishing efficiency of novel gel foam for lithium-ion battery fires

Abstract

The frequent fire issue of lithium-ion batteries (LIBs) is a significant obstacle to their large-scale applications. The existing fire extinguishing materials cannot completely solve the problems of LIB cooling, reignition, pollution, and so on. To address this issue, a new gel foam based on konjac gum (KGM) and sodium silicate (WG) was synthesized for extinguishing LIB fires. The gel foam properties, including foaming ability, foam stability, gel time, viscosity, microstructure, element distribution, water retention capacity, thermal stability, cooling ability, and fire extinguishing effect, were explored systematically. The results demonstrate that the gel foam exhibits controllable gel time, excellent adhesion property, and powerful water retention capacity. In addition, the three-dimensional network structure formed by KGM and WG effectively prevents moisture loss between the frameworks, as shown by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy. Meanwhile, the uneven distribution of silicon elements in the skeletal structure enhances the physical strength, structural stability, and thermal stability. Thermogravimetric tests display that decomposition rate of KGM/WG gel foam reaches 0.216 %/℃ and 0.036 %/℃ at 40–110℃ and 110–550℃, respectively, and the final residual content is 68.3 % at 620℃. The cooling performance and fire extinguishing experiments reveal that the KGM/WG gel foam forms an isolation layer on the surface of LIBs with a good anti-rewarming effect, which significantly inhibits the further burning of the flame. The cooling rate of the 18650 lithium-ion battery surface temperature is 3.47℃·s⁻¹, while the cooling rate of the flame temperature is 32.65℃·s⁻¹ without rewarming and reignition phenomena. Therefore, KGM/WG gel foam is considered to be a promising fire extinguishing agent for LIB fires. This study provides certain data and guidance for the further development of fire extinguishing agents for application to lithium-ion battery fires.