Study on the suppression of thermal runaway of lithium-ion battery by water mist with different additives

Water mist with additives is a promising emergency control technology for the lithium-ion battery's thermal runaway. Developing efficient, green, and environmental-friendly additive is a key issue to the technology. Here, using 18,650 batteries as the experimental object, three different suppression mechanism additives, i.e. sodium dodecyl benzene sulfonate (SDBS), sodium chloride (NaCl), and soy protein, were studied and discussed after optimizing the condition of water mist generated with different Here, using 18,650 batteries as the experimental object, three different suppression mechanism additives, i.e. sodium dodecyl benzene sulfonate (SDBS), sodium chloride (NaCl), and soy protein, were studied and discussed after optimizing the condition of water mist generated with different compressed air. The battery thermal runaway process concluded four stages, and the initial stage of explosion, i.e. the safety valve broke through companying with some noise and gases spilling out, was a typical phenomenon that suggested the beginning of thermal runaway. The water mist generated with optimized air pressure of 0.2 to 0.25 MPa, the droplet SMD size was 71-89 & mu;m, could effectively suppress the battery thermal runaway, decrease T2 quickly from about 700 & DEG;C to no more than 413 & DEG;C, and reduce the cooling time from above 1000 s to no more than 203 s. Although the mechanism of the three additives was different, all of them could evidently enhance the suppression effect of water mist on the lithium-ion battery's thermal runaway. Especially, the addition of 1.5% soy protein to water mist could decrease greatly both the flame temperature and the battery's surface temperature, and shorten 63% cooling time comparing to the pure water mist. The results showed that soy protein was an efficient and environmental-friendly additive for water mist to inhibit the thermal runaway of lithium-ion battery and had good potential practical application value. The in-depth research and analysis of SDBS and NaCl would provide basis data for the development of compound additive.