A series of BEV fires have recently occurred around the world.

In August 2024, the Mercedes-Benz EQE, Kia EV6, and Tesla Model X were reported to have caught fire in Korea, the Tesla Model 3 (press base) in Portugal, and the Tesla Semi and Rivian R1S/R1T in the US. Although the specific cause of the fire has not been announced at this stage, the fire seems to have proceeded in the process of (BMS or other abnormality) → gas emission → smoking → thermal runaway → ignition → explosion. However, since there have been many cases of spontaneous ignition while parked, not while charging, it can be inferred that the thermal management functions around the battery cells and packs may not be able to keep up due to high temperatures caused by abnormal weather in some countries.

In the case of BEVs, it is difficult to extinguish a fire if the battery cells start to smoke. In the case of BEVs, it is difficult to extinguish the fire when the battery cells are in a fuming state. In the case of BEVs, it is difficult to extinguish a fire once the battery cells have reached a fuming state due to thermal runaway, as the cell temperature can reach the 500°C level and eventually rise to nearly 1,000°C, making it difficult to extinguish the fire at this time. In the case of the BEV fire in the U.S., it was reported that firefighters were unable to extinguish the fire and had to wait until the battery burned completely.

In order to make BEVs safe, it is necessary to pursue and assume all the possibilities of such battery cells and install various safety devices. Many automakers have been trying to reduce the cost of BEVs in a variety of ways, and they have been competing to see how they can reduce the cost of batteries, which account for 40% of the total cost of BEV production. However, cell costs are expected to remain high in the future, and with increasing demands for BEV safety, it will be difficult to lower costs. BEVs with large numbers of batteries require safety measures around the batteries: not only NVH, but also cooling (heat dissipation) around cells, modules, and packs to prevent fires, and materials between cells (buffers, heat spread prevention materials, anti-flash materials, insulation/heat shields, etc.), It is important to develop and apply technologies such as cooling (heat dissipation) around cells, modules, and packs to prevent fires.

The development of BEVs and their delivery to consumers is only possible when these processes are in place. The development of BEVs and their delivery to consumers will only be possible if these processes can be reliably accomplished. As the automotive industry shifts from engine-based manufacturing to battery-based BEVs, we should seriously consider how to handle batteries and how to incorporate them into our products.