PRANAV K (STM18ME020)

SARATH K V (STM18ME024)

PRANAV N (STM18ME021)

NEERAK K (LSTM18ME034)

Over the last decade, the electric vehicle (EV) has significantly changed the car industry globally,
driven by the fast development of Li-ion battery technology. However, the fire risk and hazard
associated with this type of high-energy battery has become a major safety concern for EVs. This
review focuses on the latest fire-safety issues of EVs related to thermal runaway and fire in Li-ion
batteries. Thermal runaway or fire can occur as a result of extreme abuse conditions that may be the
result of the faulty operation or traffic accidents. Failure of the battery may then be accompanied by
the release of toxic gas, fire, jet flames, and explosion. This paper is devoted to reviewing the battery
fire in battery EVs, hybrid EVs, and electric buses to provide a qualitative understanding of the fire
risk and hazards associated with battery powered EVs. In addition, important battery fire
characteristics involved in various EV fire scenarios, obtained through testing, are analysed. The
tested peak heat release rate (PHHR in kW) varies with the energy capacity of LIBS (EB in Wh)
crossing different scales as PHRR-2EB0.6. For the full- scale EV fire test, limited data have revealed
that the heat release and hazard of an EV fire are comparable to that of a fossil-fuelled vehicle fire.
Once the onboard battery involved in fire, there is a greater difficulty in suppressing EV fires, because
the burning battery pack inside is inaccessible to externally applied suppressant and can re-ignite
without sufficient cooling. As a result, an excessive amount of suppression agent is needed to cool the
battery, extinguish the fire, and prevent reignition. By addressing these concerns, this review aims to
aid researchers and industries working with batteries, EVs and fire safety engineering, to encourage
active research collaborations, and attract future research and development on improving the overall
safety of future EVs. Only then will society achieve the same comfort level for EVs as they have for
conventional vehicles.