The enhanced cooling effect and critical control capability of nanofluids on suppressing thermal runaway of lithium-ion batteries

Abstract

Lithium-ion batteries (LIBs) thermal runaway (TR) has been highly concerned by society and scholars due to its tendency to cause considerable disasters and accidents, such as fire and explode. Rapid cooling and effective control methods play an important role in mitigating the development of disasters caused by TR of LIBs. In the present study, three types of nanofluids namely Boron nitride, Aluminum oxide and Titanium dioxide dispersed in distilled water, have been used with single concentration; 0.1 % by volume, to investigate cooling effect and critical control capacity by spray cooling in mitigation TR of LIBs. The results show that water mist containing nanoparticles can enhance cooling rate. The nanofluids can quickly reduce the temperature from maximum temperature during thermal runaway to below 100 °C in the cooling experiment, and the cooling times of 11 s, which was 45 % shorter than that of water mist. The maximum cooling rate can reach 127.4 °C/s, which is 61.29 % higher than water mist. Compared with the critical suppression temperature of water mist at 160 °C, nanofluid spray can inhibit thermal runaway at a higher temperature, and can increase the critical suppression temperature by nearly 40 °C at most. The maximum heat dissipation rate of the nanofluid spray is 6067.4 W. However, Nanofluids are difficult to suppress the rapid rise in battery temperature during TR. In addition, the cooling rate of nanofluids is closely related to their own thermal conductivity. These results demonstrate that a higher cooling rate of nanofluid spray can help firefighters quickly control TR accidents and strive for sufficient time for personnel evacuation, which may provide a reference for the suppressing disasters caused by TR.