EV fire fighting tech ... interesting product

[dnewton3]

I don't own an EV, but I think this might be of interest to EV owners.

The principle is simple; reduce the thermal energy escape and slow the reaction such that additional resources can be brought to the scene. IOW, slow the fire development rate in time for the fire department to get on scene. Conceptually it's not unlike having your own fire extinguishers in your home. Seconds count when help is minutes away!

https://firecloakusa.com/

One can purchase a single blanket for $1350. While not cheap, it may greatly help slowing fire progress in a home, if the homeowner has one of these to deploy. I would think that some insurance companies might encourage these with a discount, if not require one at some point in the future.

I also learned something from this product; EV fires are self-sustaining in that the batteries generate their own oxygen in the process of burning. That's why EV fires are so much more prolific once they start; they get into a thermal runaway state.

 

[JHZR2]

The cathode chemistries can thermally decompose, and can produce oxygen in that decomposition. But it is less than stoichiometric.

The only real solution to a battery safety event is to remove latent heat. Buying time may be helpful, but you still need to remove the heat. Otherwise separators keep melting and cells keep shorting, failures keep happening. When cell to cell propagation keeps happening, I can’t see this stopping it. I can see it reducing the chance of major fire events though.

 

[oil pan 4]

I say 8yd dump trucks full of wet sand.

 

[JHZR2]

I say 8yd dump trucks full of wet sand.

Swimming pool is better…

 

[Pablo]

And here we go.

 

[JHZR2]

And here we go.

?? Seems like a valid product to limit collateral damage and propagation to nearby EV if that’s a scenario of concern…

 

[B1974]

And who is going to get close enough to pull this thing over a high temperature burning pile of a EV fire? Maybe it should come with a Asbestos suit?

 

[dnewton3]

The cathode chemistries can thermally decompose, and can produce oxygen in that decomposition. But it is less than stoichiometric.

The only real solution to a battery safety event is to remove latent heat. Buying time may be helpful, but you still need to remove the heat. Otherwise separators keep melting and cells keep shorting, failures keep happening. When cell to cell propagation keeps happening, I can’t see this stopping it. I can see it reducing the chance of major fire events though.

I watched a YT video on this product, and they clearly say that this won't extinguish the fire; it can't because the fire self-induces the oxygen it needs. The purpose of this product is to slow the thermal exit to other items (surrounding cars, building structure, etc). Where the car would still be a total loss, perhaps the surrounding stuff could be saved. Without this blanket, the thermal runaway excites and consumes other items.

It's not a bad product IMO and might be worth owning if you have your EV stored indoors or near other vehicles.

 

[dnewton3]

And who is going to get close enough to pull this thing over a high temperature burning pile of a EV fire? Maybe it should come with a Asbestos suit?

Maybe the same person would would use a fire extinguisher to put out a small kitchen fire before it became a whole-house fire?

I'm not saying this is a perfect product which will solve all EV fire issues, but it certainly can be useful in the right conditions.

 

[4WD]

Swimming pool is better…

saw a double cement mixer truck today - let me find him…

 

[PimTac]

The worst scenario would be a EV fire in the garage. This blanket would have to be stored somewhere else and then the problem is would you be able to enter the garage? The smoke from these fires is very toxic.

So I see this product as having limited value. Maybe fire departments would have this?

 

[B1974]

False security that has limited functionality if used in time, or can't be deployed at all (unless the right PPE is used) in a real fire situation.

 

[Vercingetorix]

Blanket holds in the heat creating a Chernobyl effect. Car burns a hole in the ground and buries itself, problem solved.

 

[Pablo]

?? Seems like a valid product to limit collateral damage and propagation to nearby EV if that’s a scenario of concern…

The topic. EV fires.

Not the product itself.

 

[DuckRyder]

Seems to have a very narrow window of usefulness...

Would be interesting to see data on when/how most EV fires occur, my guess would be during charging or a crash and if when charging is it likely overnight.

 

[SHOZ]

The worst scenario would be a EV fire in the garage. This blanket would have to be stored somewhere else and then the problem is would you be able to enter the garage? The smoke from these fires is very toxic.

So I see this product as having limited value. Maybe fire departments would have this?

Hang it over the car and remote drop deploy it. Until it too is consumed.

 

[oil pan 4]

Maybe the same person would would use a fire extinguisher to put out a small kitchen fire before it became a whole-house fire?

I'm not saying this is a perfect product which will solve all EV fire issues, but it certainly can be useful in the right conditions.

Nope you can easily get cobalt poisoning from batteries in thermal runaway. I saw one in the UK a guy tried to put out some kind of lithium battery powered consumer electronics, not a car, breathed some smoke and later died.
I say don't go anywhere near a lithium battery fire.

 

[demarpaint]

Hang it over the car and remote drop deploy it. Until it too is consumed.

Or hang it on the garage ceiling then cover the car at night with it as a preventative measure.

 

[JHZR2]

I watched a YT video on this product, and they clearly say that this won't extinguish the fire; it can't because the fire self-induces the oxygen it needs. The purpose of this product is to slow the thermal exit to other items (surrounding cars, building structure, etc). Where the car would still be a total loss, perhaps the surrounding stuff could be saved. Without this blanket, the thermal runaway excites and consumes other items.

It's not a bad product IMO and might be worth owning if you have your EV stored indoors or near other vehicles.

That’s a misrepresentation of what happens. Li-ion thermal runaway occurs when the cells go over 100C and the separators melt causing an internal short. The initial cell could go up due to other reasons, but that’s a different discussion.

When cells go up, regardless of chemistry, they have their internal energy that immediately is resistive depleted, they have chemical energy in the electrolyte, and if they have an oxide cathode, can have additional chemical energy due to that decomposition. Cells with alternative cathodes like LFP can still go up and burn, propagate, etc.

The oxide cathode isn’t sufficient to self sustain a fire. It’s not. Look at material quantities and stoichiometry. A blanket is not going to keep new oxygen out. Though it can smother and deplete it.

Li-ion batteries are tight packed and the cells are hard to access. When one goes up, the heat will transfer to nearest neighbors and on and on. Regardless of if there’s a fire, remember that as the cells short internally, a massive amount of electric energy is removed and goes to heating neighbor cells. That’s why it will continue onward. You could inert the local area with co2 or halon and the heat would still be there. As soon as ambient oxygen creeps in, fire will flare again. But cells will keep cooking off in the interim.

You need to remove the latent heat.

 

[oil pan 4]

That’s a misrepresentation of what happens. Li-ion thermal runaway occurs when the cells go over 100C and the separators melt causing an internal short. The initial cell could go up due to other reasons, but that’s a different discussion.

When cells go up, regardless of chemistry, they have their internal energy that immediately is resistive depleted, they have chemical energy in the electrolyte, and if they have an oxide cathode, can have additional chemical energy due to that decomposition. Cells with alternative cathodes like LFP can still go up and burn, propagate, etc.

The formation of pesky ron Jeremy dendrites because of charging too fast, charging too fast when cold, ect.
Oh and don't forget the anode is made of coal which you know...