The subject of three patent deposits, the integrated Hyundai Mobis system to prevent the fire from an electric vehicle battery is probably a world first.
For passenger safety
As with petrol and even diesel models, accidents of electric cars have already caused the death of their occupants when they were followed by the conflagration of vehicles. In thermal devices, it is most often a fuel leak that causes the fire. On a VE, it is the battery that poses a problem on this subject.
Currently, in Europe, China and India it is imposed that the thermal runaway caused after the departure of flames for at least one cell of the pack is delayed at least five minutes. An insufficient time when people aboard the vehicle cannot go out by themselves, either because they are unconscious after the shock, or because the doors remain blocked.
During an interview that I carried out for another media, Lieutenant-Colonel Michel Gentilleau told me that he wanted to increase this time for him to approach the time. This is what he defends in his current functions with the EURO NCAP after being in charge of training firefighters and people affected by accidents and fires of alternative energies.
In its press release dated April 14, 2025, Hyundai Mobis even specifies ” that some countries harden their regulations to prevent any thermal transfer ».
Prevent heat transfer to adjacent cells
The tightening of constraints in favor of the safety of transported people pushes manufacturers of electric vehicles to find solutions to counter or prevent thermal conflagration of cells in the batteries.
The system imagined by Hyundai Mobis prevents heat transfer to adjacent cells. How ? By extinguishing the flames quickly by spraying an extinguisher agent within 5 minutes of their appearance. This precise scenario which blocks the propagation of heat to nearby units is presented by the company as a world premiere.
It is based on a set of devices, starting with the use of an anti-supercudious material. Qualified as ” Pulsating heat pipe “, What can be translated as” Caloduc pulsé ”, it is made up of an aluminum alloy and a refrigerant. By arranging it between the cells in the lithium-ion modules, it has the effect of lowering the internal temperature of the battery.
-Because it is able to manage heat reliably, this thermal management system could develop according to Hyundai Mobis, with a beneficial role also during fast recharges.
Target pressure spray
In order to overcome the warm -up and flames, the battery system would contain a fluid of a capacity five times greater than that of a domestic extinguisher of 3.3 kg. According to the Korean equipment supplier, this agent would present ” excellent cooling, insulation and permeability properties ». It would also be ” harmless to the environment and the human body ».
The subject of one of the patents, a network of pipe would be the role of transporting the extinguisher agent to the right place which would then be pulverized at high pressure. The whole would work away from a specific case under the control of software capable of taking ” Rapid and precise decisions in the face of any physical modification of the battery system ».
In order to rule out interpretation errors, this software would be based on ” a redundant algorithmic structure »From the data collected in real time by sensors which will allow to analyze the temperature, voltage and pressure of the battery in order to detect any anomaly.
If necessary, the software would define the places where the extinguisher agent should be pulverized. This organization required the development of a unprecedented battery management system (BMS).
A solution to generalize?
« With the arrival of large electric vehicles with improved autonomy, the safety systems safety standards are becoming more strict. We will integrate hardware and software to develop advanced battery systems that meet and exceed global standards, and launch them on the world market », Highlights Park Yong Jun, Vice-President of the R&D Group Battery Systems at Hyundai Mobis.
If this solution should be perceived as sufficient and effective to prevent any thermal runaway from the batteries, it would benefit from being used by other manufacturers who would not have a similar device. At this level of development, the additional cost to equip electric cars whose prices are still high has not been communicated.
The generalization of such a system would be likely to erase fears and criticisms concerning the potential risks and damage caused by VE fires, including potential residual pollution and large volumes of water used for extinction.
