A comparative study on the suppression capacity and the environmental impact of different extinguishing agents of lithium-ion battery fires

Lithium-ion batteries (LIBs) represent the technology currently used in laptops, smartphones, electrical vehicles (EVs), plug-in hybrid electric vehicles (PHEVs), and energy storage system (ESS). The choice over LIBs is due to their low weight, high energy density and charging capacity. However, the increase in use has shown the limits of these devices, especially if subjected to electrical, mechanical, or thermal abuse. Moreover, news on fires involving LIBs is increasingly frequent. Fire suppression and rapid cooling methods would help to mitigate or even eliminate the battery fire hazards. In order to identify an efficient suppression system for LIBs fire, tests on NMC Kokam lithium-ion pouch cells, with different capacity (25Ah and 40Ah), were conducted using different extinguishing agents, such as water mist, water with F500 additive and CO2. By combining the cell temperature measurements and videos recorded by camera it was possible to obtain information on timing of the main events and the effect of extinguishing agents. Furthermore, at the end of the fire tests, the solid and liquid residues were sampled to evaluate their composition through Gas-Chromatography (GC) and Induced Coupled Plasma (ICP) to determine the Volatile Organic Compounds (VOCs) and metals trace. This information is also useful to identify the environmental impact of different extinguishing agents and for post-fire soil management in the case of large-scale accidents.