Source: There are "fillers" between cells that are endothermic, heat absorbing. This reduces the risk of a complete pack event. There are "separators" within the cells that upon heating, block ion transfer, turning off energy release by the cell. As for relative risks: NMC/NCA - heat and fire LFP - toxic gas with a lot of explosive hydrogen I am leaning towards battery pack safety regulation that incorporates both the "filler" around the cells and "separators" within the cells. Not something that needs to be done instantly and should not specific the specific media. Rather, a performance based, benchmarked solution. Bob Wilson
I consider my Tesla battery pack safe, while poorly designed NCA/NMC can be unsafe. LFP is safer, but of course you can mis design the pack and the battery management system to be less safe.
My takeaway was an endothermic filler between the cells. The fire hazard of Sherman tanks was resolved by ‘wet’ storage. The tank round racks had thin, antifreeze filled walls. This greatly reduced ‘cook off’ giving crews time to get out and often leaving a tank that could be repaired. Bob Wilson
My take away was tl:dr the full thing. On a vehicle carrying hazardous waste I can see heavy regulation to make it as safe as possible. But what is it, EVs have less than 2% of the fire risk of vehicles carring an ice and a gasoline or diesel tank. Those EVs using LFP even have less risk (other than being heavier may cause more damage to what they hit). The perfect should never be the enemy of the good, and waiting for perfect (solid state) and keeping the mediocre until then is even worse.
All vehicles have risks. EV risks are different and thankfully less bad than ICE and some hybrids. We are about 20 years into adoption of high energy batteries and lessons are being learned. Being aware, we can mitigate the different risks. Bob Wilson