OT: Korean battery fire

That looks like the discharge from a dry powder extinguisher.

I'm confused here. Several seemingly sensible sources on the web, one for example

This also talks about water:

nib

IIUC Its is quite common - but you need *loads* of it to not only extinguish the fire, but also bring the temperature right down - otherwise it just spontaneously lights again.

That the problem with EVs that have already caught fire. Once extinguished they can catch fire again. This is the reason for the suggestion of dumping the vehicle on a tank of water or when recovered keeping them well away from other vehicle in a pound or garage forecourt.

One company has tested a cryogenic method of stopping a lithium battery fire.

If you cool the battery enough, you can stop the fire.

But this is not very practical.

Maybe some day, there will be a cryogenic inlet on the pack housing, for fire suppression. Then, the volume of LN2 or whatever, would be less.

It's all a question of thermal conductivity, and whether you can get the "cold", close enough to the runaway chemical reaction in the battery.

Using massive quantities of water, to cool to ambient temperature, is not really a good substitute for a cryogenic (below ambient) fluid. But transporting a lot of water, is easier to do.

Paul

Water doesn't work very well because lithium ion batteries can burn happily under water. Think of them as fireworks with their own oxidant.

But the old triangle of fire. If you can't remove the fuel, and you can't remove the oxygen (from a self-contained exothermic reaction) then your only option is to remove the heat. And water does that quite well for a cheap and easily available option.

nib

Quenching Lithium battery fire in water (10 second video)

Notice how the video stops and it is still burning fiercely

The broken English in this article does not help, but both the anode and cathode have decomposition reactions that happen to release oxygen.

What I'd like to know, is whether immersion in liquid nitrogen, has the ability to chill the materials, versus the LN2 boiling so vigorously that heat cannot be carried away, with effect.

Paul

Surely boiling vigourously means that it is absorbing heat from its surroundings, at a great rate?

That article is about Lithium Ion batteries, but the batteries made at the factory which caught fire are lithium thionyl chloride batteries - a type of lithium metal battery. In these, metallic lithium is used as the anode.

Lithium metal batteries are non-rechargeable. They are long lasting, and are used in pacemakers, for example.

What's particularly sad about the fire is that there were two fire exits on that floor of the factory. The dead workers were all overcome by fire/fumes before they reached the exit. It took a while for the fire to take hold, and I suspect that if all the workers had run at the first sign of trouble they'd have made it out safely.

Just curious, where do we "know" that from so soon after it happened?

- a type of lithium metal battery. In these, metallic

Also used in smart gas meters for a 10+ year life.

But you wouldn't necessarily want to be anywhere near a car battery fire doused in liquid nitrogen. The heat from the battery fire could result in one litre of liquid nitrogen becoming 700 litres (0.7m3) of nitrogen gas resulting in an oxygen deficient atmosphere and asphyxiation.

The firm is called Aricell. That's what they make.

That's reassuring! ;)

Thanks, the only "reporting" I'd heard was that the cells in question were waiting to be assembled into PV storage batteries, which wouldn't make sense for primary cells ...

But that's what your SCBA is for.

I agree it would be a bummer for the bystanders :-)

Paul

Agreed. I suppose it's possible that the company suddenly decided to branch out into a new product line?