r/science Sep 10 '23

Chemistry Lithium discovery in U.S. volcano could be biggest deposit ever found

https://www.chemistryworld.com/news/lithium-discovery-in-us-volcano-could-be-biggest-deposit-ever-found/4018032.article
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u/vkashen Sep 10 '23 edited Sep 11 '23

If the battery is ruptured and the substrate is exposed to atmo then it's "good luck trying to put it out," it's damn near impossible. There are a few techniques to try to coat the car/battery area with foam or just hitting it hard with the hose for an extremely long time, but it's still no guarantee. Plus, even if you do manage to extinguish the battery fire, once it dries it can spontaneously re-ignite a few minutes or even a few hours later as lithium-ion batteries simply do that when exposed to oxygen. It's a very different situation than an internal combustion engine and gasoline (of course quite dangerous too), and we have to be both careful and quick as you never know if there's a rupture or not, so it's extremely dangerous. I'll work the scene, but I'm far, far more careful to listen for sounds that may indicate this possibility.

As for "less likely to catch fire," well, that's a different set of variables. On one hand, there's no fuel tank to rupture so no gasoline all over the road and the car(s) and other flammable fluids, so a stray spark won't ignite the vehicles & people in that regard, but the big concern is that it's often difficult to know if the battery reqgion has ruptured and can ignite spontaneously at any moment and if it does, it's really, really bad. There is a lot of protection around the battery, though, to prevent ruptures, but nothing is perfect. And different manufacturers engineer their protection in different ways, so they are not all the same.

To be honest, I've yet to see statistics on the safety of an EV over a "normal" car, and as every MVA is different, there are so many variables that I wouldn't even want to hazard a guess as that's all it would be. But I will say that when an MVA involves an EV, it's "Watch out guys and be careful, it's an EV" is one of the first things we'll hear from the incident commander or dispatch, so in my mind, it's hard to know which is more dangerous. I definitely like not having to worry about gas all over the place that hasn't ignited, but I've seen EV packs ignite with incredible force, and even hours after the MVA, so personally I see it as a crapshoot.

tl;dr: I'm not certain as I haven't seen any statistics and EVs are still a small percentage of cars on the road, so I'm not sure. But I'm far, far more careful when I respond to an MVA involving an EV and it's not just a ding. If it's bad, and a rupture is possible, we're definitely more on edge.

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u/1668553684 Sep 10 '23

Thank you for the response! Everything here definitely makes a lot of sense.

One last thing, do you think that fighting EV fires will become easier as more people start driving EVs and we develop a better understanding of how to deal with EV fires (not only on a firefighting level, but also up to and including a manufacturing and safety standards level), or would you say that the problems with EV fires are sort of "immutable" characteristics of the materials used?

I.e. would you attribute some level of difficulty to the novelty of the technology?