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As lithium-ion cells and systems become larger and more ubiquitous in automotive applications, fire and explosion hazards that are rare or non-existent in smaller systems may exist in these larger systems. One potential hazard can occur when flammable gases emitted from a lithium-ion cell failure accumulate in or around automobiles and are ignited by electrical activity or by the cells themselves and result in a fire or explosion. In some instances, the safety aspects related to fires and explosions protection of electric vehicles and hybrid vehicles using these large energy storage battery packs are a significant challenge to address. This paper describes and characterizes the combustion and explosion hazards that can occur when a lithium ion battery pack fails and goes into thermal runaway in an enclosed space. Metrics such as gas composition, maximum overpressure, rate of pressure rise, and flammability limits are described.

The emergence of Plug-in hybrid electric vehicles (PHEVs) and electric vehicles (EVs) as a viable means of transportation has been coincident with the development of lithium-ion (Li-ion) battery technology and electronics. These developments have enabled the storage and use of large amounts of energy that were previously only possible with internal combustion engines. However, the safety aspects of using these large energy storage battery packs are a significant challenge to address. In addition, the rapid advances in electrode and electrolyte materials for Li-Ion batteries have made comparisons and ranking of safety parameters difficult because of the substantial variations in cell designs. In this work, we outline a method for quantifying the thermal safety aspects of Li-ion battery technologies using a Cone Calorimeter.

While ignition of flammable and combustible liquids by hot surfaces is a well-known hazard in the automotive and aviation industries, there are limited studies on the ignition characteristics of the increasingly popular automotive biofuels, such as ethanol blended fuels and biodiesel. In this paper, we present the results from over 600 ignition tests using a reproducible testing apparatus which includes: a temperature controlled hot plate, a controlled volume of liquid injected onto the hot surface and a quiescent environment. Tests were conducted to study the ignition characteristics of these biofuels and compare the results to commonly used gasoline and diesel. Hot surface tests were conducted using 100% ethanol, E85 (85% ethanol and 15% gasoline), gasoline, diesel, E-diesel, biodiesel B100, and B20 (20% B100 and 80% diesel). Based on the results of the tests, the propensity for the various fuels to ignite on a hot surface was addressed.