L-320 - Comparison of Li-Ion Battery Thermal Threat and NATO Standardized FH Threat

The main failure mode associated with the lithium-ion (Li-ion) battery technology is known as thermal runaway, which is a highly energetic reaction involving the violent combustion of flammable electrolytes. As there is an increase in use of Li-ion batteries within munition systems or in various applications used around munition systems, the hazards associated with thermal runaway must now be considered in the safety assessment of munition systems. This begs the question, how does the thermal threat associated with a Li-ion battery fire compare with NATO’s insensitive munitions (IM) standardized fast heating (FH)
threat, which was mainly defined by fuel fires.

This report presents an overview of the hazards associated with Li-ion batteries and summarizes the requirements for the IM standardized FH threat. Using results from characterization studies of Li-ion battery fires, a comparison is made between this threat and the requirements for the IM standardized FH threat. Expected temperatures from a standardized FH test are likely comparable to the average temperatures seen in Li-ion battery fires as the combustion of the flammable organic electrolyte, a hydrocarbon fuel fire, seems to be the main contributor of a Li-ion battery fire. Since Li-ion battery fires temperatures can range from approximately 550°C to 1500°C the standardized FH test may not replicate the maximum temperatures and other potential consequences that can result from this new threat.