Experimental Study on the Efficiency of Hydrogel on Suppressing Thermal Runaway Propagation of Lithium-Ion Battery

To promptly and efficaciously extinguish fires involving lithium-ion batteries and address the issues of prolonged firefighting duration and substantial water usage within the domain of fire safety, this study explores the suppressive impact of hydrogel on the thermal runaway in high-capacity lithium-ion batteries utilized in electric vehicles. Firstly, the 135 Ah lithium-ion battery used in electric vehicles was used as the test object, which was subjected to thermal runaway through electric heating. On this basis, water and hydrogel fire extinguishing experiments were carried out. Secondly, the microstructure of the hydrogel after heat treatment was observed under environmental scanning electron microscope. The results show that hydrogel has better cooling and thermal runaway control effects than water. The cooling effect of 10 kg hydrogel can be twice that of 20 kg water. At the same time, the interval time of prolonged thermal runaway propagation of hydrogel is more than three times that of water with the same dose, which can bring longer safety time for rescue and escape. Furthermore, the superior cooling mechanism of hydrogel is attributed to its ability to adhere to heated surfaces, thereby enhancing the utilization of its internal water content for sustained cooling.