Cold Cut Systems and Volvo Car Corporation are collaborating in projects to develop a safe, efficient, and sustainable method to extinguish fires in Li-ion batteries.
In the Euro RESCUE app, a method that combines internal cooling with a cutting extinguisher and a special foaming additive is advocated by one car manufacturer. The aim of the first project was to verify this method as a basis for a generic method. As a second step, the goal was to carry out experiments with injecting Aqueous Vermiculite Dispersion (AVD) to stabilize the battery after the intervention. The project’s method approach was consistent, as the general goal was to find a practical method for extinguishing a fire in a Li-ion battery pack.
A total of four controlled tests were conducted on two Plug-in Hybrid Electrical Vehicle (PHEV) batteries and two Battery Electric Vehicle (BEV) batteries. Propagation was started by overcharging/overheating. The intervention started with a 15-minute report time after the first visible or audible activity in the battery. For practical and safety reasons, the maximum intervention time was set to 20 minutes.
The experiments with additive showed no significant effect on the battery propagation compared to water only. The supplier of the foam additive has to show further research and testing results to prove their method. The experiments with AVD indicated that the aqueous vermiculite had difficulty attaching to surfaces in a battery that was already affected by water or water with additives.
A test using the Cobra cutting extinguisher on a BEV-battery, using water only as extinguishing medium, showed the best results: the fire was extinguished in less than 20 minutes, and after just over a week in quarantine (where the battery pack had been provoked by handling every day), 11 of 27 battery modules still held charge – indicating that the experiment had successfully stopped the propagation. The results were in line with Volvo Cars’ knowledge and experience in the field.
Overall, the project showed that it is possible to stop propagation in a battery pack by means of internal cooling with water using the Cobra cutting extinguisher. To develop a generic method from these results, additional research and tests are required based on combined knowledge and experience from the Fire and Rescue Services and the industry.
We aim to start a second project develop a safe, efficient, and sustainable method. The objective is for this method to be generic and practical for Fire and Rescue Services on how to access and extinguish propagating Li-ion batteries (including electrical vehicle fires). The objective is also to present the obtained results, to contribute to clarity on the matter on the market.
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