Giant's "fire blocker" battery design

[caleb7]

This design prevents all Li-Ion cells from catching fire at once, EMBN claims. According to video, "the plastic is designed to melt around the cell". I couldn't find more info, but do you think this really works? Even if it does, many of us probably can't test if our DIY version of this would work.

Sorry if this has been talked about before, or if this is something old.



The above image is a screenshot from this YouTube Shorts video:

 

[A-DamW]

This design prevents all Li-Ion cells from catching fire at once, EMBN claims. According to video, "the plastic is designed to melt around the cell". I couldn't find more info, but do you think this really works? Even if it does, many of us probably can't test if our DIY version of this would work.

Sorry if this has been talked about before, or if this is something old.

This may be a fun read:
PaulD's Experiments with Endothermic Potting Compounds

 

[neptronix]

I'll believe it when i see a safety test!

Lithium cells burn at ~3000F, which is enough heat to melt aluminum and steel. AFAIK, the most heat tolerant plastic melts/burns at 600F.

Here's what a Tesla looks like after a battery fire. Tesla has likely made the strongest effort in industry to make their batteries safer.. yet.. they still spontaneously combust and then melt due to the ultra high temperatures ( aluminum melts at ~1200F )

I'm pretty sure the source for this claim is 'i made it up'

 

[A-DamW]

This conversation makes me want to design all my battery packs with a quick swap/emergency eject system...

 

[jkrienert]

I'll believe it when i see a safety test!

Lithium cells burn at ~3000F, which is enough heat to melt aluminum and steel. AFAIK, the most heat tolerant plastic melts/burns at 600F.

Here's what a Tesla looks like after a battery fire. Tesla has likely made the strongest effort in industry to make their batteries safer.. yet.. they still spontaneously combust and then melt due to the ultra high temperatures ( aluminum melts at ~1200F )

I'm pretty sure the source for this claim is 'i made it up'

View attachment 344757

Did that tesla burn that whole area, or did the area burn the tesla?

 

[docw009]

Newer lithium cells are rated to take a short circuit without fire/explosion, They also have a crush test, Some can take some arbitrary overcharge for an hour, I think that pressure vents and CID's must allow them to break the circuit internally and/or vent before the insides can get hot enough for thermal runaway.

People recycling older cells, or re-using really old batteries, maybe those are bigger fire risks,

 

[Chalo]

Tesla has likely made the strongest effort in industry to make their batteries safer.. yet.. they still spontaneously combust and then melt due to the ultra high temperatures ( aluminum melts at ~1200F )

It makes me wonder... it seems obvious to me that given equal process control, using 6000 tiny cells will result in a larger number of critical failures than using 100 big ones. What I don't know is whether this principle is reflected in the available data on commercial EVs.

 

[caleb7]

This may be a fun read:
PaulD's Experiments with Endothermic Potting Compounds

I didn't see that thread, interesting indeed, thank you.

This conversation makes me want to design all my battery packs with a quick swap/emergency eject system...

Would be interesting to see if such system ejected a burning cell at home. Probably much better than entire pack bursting fire.

 

[neptronix]

Did that tesla burn that whole area, or did the area burn the tesla?

There's numerous images of semi-melted Teslas on the internet due to battery fire. In these cases, the battery burned the tesla and the area around it

 

[neptronix]

Newer lithium cells are rated to take a short circuit without fire/explosion, They also have a crush test, Some can take some arbitrary overcharge for an hour, I think that pressure vents and CID's must allow them to break the circuit internally and/or vent before the insides can get hot enough for thermal runaway.

People recycling older cells, or re-using really old batteries, maybe those are bigger fire risks,

Tesla has had all this stuff on lithium cells for ages. They still randomly catch fire, short circuit or not. One cell can set off the entire pack due to the sheer amount of heat. The problem is the chemistry used. Lifepo4, solid state, sodium ion, and a few other chemistries are nowhere near as volatile of flammable.

It makes me wonder... it seems obvious to me that given equal process control, using 6000 tiny cells will result in a larger number of critical failures than using 100 big ones. What I don't know is whether this principle is reflected in the available data on commercial EVs.

I would think this is the case too. You just need 1 cell with an internal defect to melt down the entire pack. Statistically speaking, the more cells, the higher chance for a fire sounds right. But it may not be true, the risk could actually just be the amount of battery materials per square inch even if you had huge cells.

What would be the difference in net safety between both designs? probably a few percent. Not enough to mitigate the achilles heel of these sorts of chemistries i think.

At this point in my life, i'm a more risk averse about lithium batteries. I really want some high energy density ( ~150whrs/kg ) lifepo4, sodium ion, solid state, etc on my next bike, even if that makes my bike a bit of a tank.

 

[jonyjoe303]

I seen videos before of NASA also doing tests on lithium cell batteries being encased in cylinders holders similar to the ones mentioned. On the videos I saw, when a cell caught fire it was from the ends and the casing did prevent the other cells from catching fire.
But on the test I saw the battery was out in the open, not enclosed inside a box etc, in real life if a cell catches fire its going to catch the box/wiring etc on fire, then all the cells will probably go off also. The holders might survive the inferno but everything else not so much.
Lifepo4 might not be as prone to catch fire as other cells, but when they go off it will be just as flammable as any li-ion cell, it goes up like a blowtorch from my experience.

 

[offGridDownUnder]

a quick swap/emergency eject system...

I have an image in my mind now of an e-bike rider rolling along at speed firing burning Li cells at the cars and buildings as they pass by.

 

[999zip999]

I agree just like a bottle rocket the energy is going to have to go somewhere. Lithium ion fire it's not easy to put it out with water. Or a device.
Okay it's like the fireproof safe for your batteries in your bike shop or store you have to vent it outside through a metal pipe just like a fireplace chimney.
Or else you can make a bomb cabinet and just lock the door shut. Yes full of batteries probably with chargers on them.

 

[Chalo]

Lithium ion fire it's not easy to put it out with water. Or a device.

When there was a big pedicab shop fire here a while back, it kept the fire department busy all night and into the next day. They were able to extinguish the fire relatively easily (even the lithium batteries), but after an interval the batteries would light themselves back up. So the place had to get hosed down again and again.

 

[neptronix]

..that's the issue, lithium batteries go into thermal runway at approximately 150C or 300F. And they can sit there soaking in heat and suddenly go off, then ignite other batteries.

When lithium batteries catch fire, their heat output can be up to approx 1650C or 3000F.

It's a huge problem.

I'm ready to hop on the sodium ion, solid state, or LTO train myself