26 Jun 2023

Analysis of combustion gases from large-scale electric vehicle fire tests

Alternative Fuel Vehicles

Alternative Powered Vehicles

Current Affairs in Fire & Rescue

Lithium battery fires

Authors

Jonna Hynynen, Ola Willstrand, Per Blomqvist, Petra Andersson

Publisher

arch Institutes of Sweden RISE, Department of Fire and Safety

Fires involving electric vehicles have attracted considerable attention in the media. In particular, the toxic gases released upon combustion of electric vehicles and lithium-ion batteries has been a major concern. A RISE study of these issues is now published in a 2023 Fire Safety Journal.

Fig. 1. Schematic overview of the test facility and test setup. The collector hood skirt was not used for tests 1–3. This schematic is reprinted with permission from Ref. [17].

In this study, the results of six large-scale vehicle fire tests are presented including three electric vehicles, two internal combustion engine vehicles, and one electric vehicle with the battery pack removed.

Additionally, separate battery component tests were performed. In two of the vehicle fire tests a sprinkler system was used to assess the effect of water application on the combustion gases. Furthermore, calculations of the heat release rate, peak heat release rate and total heat release were performed, as well as chemical analysis of gas and soot.

Peak heat release rate and total heat release were affected by the fire scenario and vehicle model, but not significantly by the type of powertrain.

Regarding the combustion gases, hydrogen fluoride represented the largest difference between electric vehicles and internal combustion engine vehicles.

Additionally, battery specific metals such as manganese, nickel, cobalt and lithium were found in higher concentrations in the electric vehicle tests than in the internal combustion vehicle tests, in which larger quantities of lead were found.