Study On Thermal Runaway Domino Effect Of Lithium-ion Batteries In Air Transportation

With the development of battery technology and the widespread use of lithium-ion batteries,the safety of air transport lithium-ion batteries has attracted widespread attention from domestic and foreign civil aviation organizations.A large number of batteries are tightly arranged in the package for air transportation,and the thermal runaway of one battery can easily cause the thermal runaway of the adjacent batteries,which will cause the entire package of batteries to run out of control.Therefore,studying the thermal runaway domino effect of lithium-ion batteries has become a key factor in ensuring the safety of lithium-ion battery air transportation.In this paper,a self-designed lithium-ion battery thermal runaway platform is used to study the domino effect of thermal runaway of the lithium-ion battery.From the perspective of the thermal runaway energy release rate,total amount,and transfer efficiency of lithium batteries,experimental research on different temperature rise rates,state of charge and thickness of the separator,observe the thermal runaway phenomenon of lithium battery module,analyze the thermal runaway spray flame and expansion rule of lithium ion battery.Simultaneously analyze the thermal runaway time node,surface temperature,and mass loss,and compared the heat transfer efficiency under different thickness conditions.The results show that the temperature rise rate of thermal runaway batteries has a greater impact on the thermal runaway of neighboring batteries,and the critical temperature rise rate of the thermal runaway domino effect of the lithium battery pack is 29°C / min.The heating rate before the initial explosion of the battery is also different,and the fitting value at 60°C / min is 2.1-4.3 times that at 10°C / min.With the increase of the state of charge,the thermal runaway of the lithium battery module is more and more likely to form a domino effect.As the thermal runaway time passes,the increase in total energy released by the lithium battery module makes the next battery easier and faster thermal runaway.Spread faster.Under the conditions of the open test chamber,the lithium battery loses 4504 J of heat,which is about 20.5% of the energy it releases.Except for direct contact with the heating rod battery,the maximum temperature drop of the lithium battery pack when the separator is added compared to the separator without the separator is 53°C,523°C,and 489°C,respectively.Corrugated paper separator can significantly reduce the heat transfer efficiency between lithium batteries.When there is no partition to a single partition,the heat transfer efficiency is reduced from 27.7% to 17.6%,and the degree of decrease is 36.5%.When one partition to a three-layer partition,the heat transfer efficiency is reduced from 17.6% to 12.8%,and the reduction is 27.3%.The research can not only provide reference suggestions for revising the relevant standards for lithium-ion battery air transportation,but also provide theoretical guidance for the safe design of lithium battery packaging.