Effect of Low Temperature on Thermal Runaway and Fire Behaviors of 18650 Lithium-Ion Battery: A Comprehensive Experimental Study

To investigate the effect of operating temperature on the thermal runaway (TR) and combustion behavior of lithium-ion batteries(LIBs), a series of LIB thermal abuse experiments were performed after cycling at different temperatures and cycle rates. Local heating of the electrothermal film was used to simulate the abuse process triggered by the TR of adjacent LIB in the module. Combustion behavior, cell surface and flame temperatures, thermal radiation and mass loss were measured. For the cell cycling at 0 degrees C, the amount of gas in the exhaust phase was obviously reduced, and the intensity of flame combustion was reduced. For the battery after cycling at - 10 degrees C, deflagration occurred within 2 s after the safety valve cracked. The experimental results show that the onset temperature of TR of LIB decreased significantly with the operating temperature decreasing from 25 degrees C to - 10 degrees C. Low-temperature cycling causes safety valve cracking and TR to occur earlier. This work presents in detail the characteristics and mechanism of TR behavior changes of LIBs at low temperatures, which provides guidance for process safety assurance and fire protection design for the practical engineering applications of battery at low temperatures.