Explosion characteristic of CH4–H2-Air mixtures vented by encapsulated large-scale Li-ion battery under thermal runaway

Abstract

Explosion-proof diesel-powered vehicles are the main auxiliary transport vehicles in underground coal mines, although many of these have been replaced by battery electric vehicles (BEVs) nowadays. The explosion-proof structure and performance of the power supply of the BEVs should meet the IEC 60079 standard, however, and the explosion-proof cavity where the batteries are placed should be able to withstand a static pressure of not less than 1.5 MPa. In this paper, a nail penetration experiment is carried out on an encapsulated lithium-ion battery (LIB) pack under an atmosphere consisting of air, 9.5% methane, and 12.5% mixed combustible gas, and the temperature and the pressure data of the thermal runaway LIBs in the explosion-proof tank are comprehensively analysed. Moreover, the ignition explosion test of the gas released by thermal runaway of LIBs in different environments is conducted. Finally, the explosion process is simulated by the chemical reaction kinetics model in Ansys Fluent. The experimental and simulation results can guide the structural design of the explosion-proof tank of the power supply in extreme working environments, and provide an important reference for explosion-proof protection design and overall integrated safety design of LIB power supplies for explosive special environments.