Can LiFePO4 Batteries Combust in Thermal Runaway Event?

[740GLE]

Please don't get news or technical information from FB on anything.

Agreed, go to YouTube and forums for technical information

 

[DerpsyDoodler]

Agreed, go to YouTube and forums for technical information

And always verify the information from multiple sources. Youtube and forums are fallible, as well.

 

[Gazoo]

I don't mate. I just corrected some people who were saying lifepo4 explode into flames and vent toxic gas then this tool decided to try and flex his "expertise" lol. I get all my info from Will's YouTube/blog or industry professionals

There is much to be learned from those that are not professionals. Sometimes peoples posts of hands on experiences are intriguing and much can be learned from them as well. And some who claim to be "industry professionals" have opinions with little to no data to back it up. And if they do have data it might be old data.

Personally I learn something new every day from this forum so I can never claim to be an expert because of all the variety of things that can be learned here from other's experiences.

 

[Just John]

And can anyone confirm the casing on these cells is in fact this dangerous and any contact with metal can cause a short circuit?

Internally, one of the terminals is constructed of aluminum. That is part of the battery chemistry that makes it work. Yes there is a charge on the exterior case. No, it is not connected to the positive terminal. The current it can generate is small, it is missing some of the other coatings present on the true cell positive to carry a substantial amount of current. This is why they wrap the cells.

 

[Msg43]

The electrolyte is flammable. If a cell is physically damaged, you can catch it on fire. But for an exothermic reaction to occur to cause combustion, from the literature I've read, is impossible with lifepo4. Well, unless you had a pile of kindling next to a spark generator of sorts ? or a dead short next to a fuel source. But to have combustion caused internally, is impossible.

@Will Prowse Could you clarify why the battery behavior in the “spearing” video isn’t an exothermic reaction resulting in combustion? It doesn’t seem like the spear provided a spark. It looks like a second major puncture resulted in a fire, no?

 

[Will Prowse]

@Will Prowse Could you clarify why the battery behavior in the “spearing” video isn’t an exothermic reaction resulting in combustion? It doesn’t seem like the spear provided a spark. It looks like a second major puncture resulted in a fire, no?

That is literally impossible. Not exothermic.

Electrolyte is flammable, something caused initial combustion event and electrolyte burned.

I think you should recreate this event in a laboratory. Pretty sure the second puncture caused combustion. Those cells are hermetically sealed for good reason. But it is impossible to have self propagating thermal runaway with lifepo4. But that electrolyte will burn.

 

[curiouscarbon]

physical collision causes friction based heating. a spark to ignite existing hot gasses. physical compression to connect internal voltage gradient, resistive heating moment to heat and ignite exiting hot gasses.

LFP still is less violent than other chemistries.

treat the battery cautiously, less failure expected.

 

[curiouscarbon]

LiFePO4 cells can combust.
Low chance of cell thermal runaway.
High resistance connections can ignite gasses.

this video is NOT LFP.

it is one of the worst cases.

 

[Just John]

That is literally impossible. Not exothermic.

Electrolyte is flammable, something caused initial combustion event and electrolyte burned.

I think you should recreate this event in a laboratory. Pretty sure the second puncture caused combustion. Those cells are hermetically sealed for good reason. But it is impossible to have self propagating thermal runaway with lifepo4. But that electrolyte will burn.

What it looked like to me (I wasn't there, just observation). The first puncture shorted the cell internally and the heat started the electrolyte boiling. The second puncture seemed to let in just enough oxygen to let the boiling electrolyte ignite due to the heat of the short. The flame was the (very toxic) electrolyte boiling and igniting. Unlike other lithium chemistries, the chemistry doesn't produce its own oxygen triggering an exothermic reaction.

 

[Supervstech]

Keep in mind, a stack of wood is very combustible, yet we all live in houses built out of it.
Install proper safeties and LFP is very safe. Install no safeties, or do a bad job, and that stack of wood won’t survive long.

 

[wattmatters]

Just to clarify the use of the term "exothermic".

Exothermic means more heat (energy) is released than is used to start and sustain the process. It does not mean thermal runaway.

A thermal runaway of an NMC cell is clearly exothermic.

A camp fire is also exothermic, as is a burning candle.

If the electrolyte from a LiFePO4 battery cell has somehow been ignited and continues burning because it has an external supply of oxygen (like a camp fire or candle does), well that is also exothermic.

The thermal runaway, of e.g. an NMC cell, is just a very highly exothermic reaction. Obviously since the reaction supplies its own oxygen in a concentrated form and in close proximity to feed the reaction further, it ends up being an ongoing fustercluck, all but impossible to control. Just ask the owners of Felicity Ace, now keeping company with Davy Jones's locker.

If someone manages (quite hard) to get the electrolyte from a LiFePO4 battery to start burning and it has an external supply of oxygen to keep on going, well that's still an exothermic reaction. But since sustaining it relies on external supply of oxygen, it is way easier to mange since, unlike an NMC thermal runaway, you'll be able to cut the flow of oxygen. In the absence of an oxygen supply a LiFePO4 cell may still continue to vent (unpleasant and not healthy) but not burn.

 

[jhooligan65]

I would like to challenge anyone reading this to find a photo or video of a LiFePO4 creating internal combustion from thermal runaway event.

I keep seeing people comment that LiFePO4 can combust, but UL listed companies and battery studies are telling me otherwise. Where are people coming up with this idea? LiFePO4 raw cells are being constructed in packs without individual cell fusing, and no one is blinking an eye.

But there are articles from reputable people (Jack Rickards videos as well) stating that they can combust.

So if someone can PLEASE email me evidence of LiFePO4 combusting from thermal runaway, I would love to see it (my email is willprowseiv@gmail.com)

Here is some of my proof that LiFePO4 is NOT combustible:
https://www.osti.gov/servlets/purl/1395736
https://relionbattery.com/uploads/images/misc/Relion_SafetyLithiumBattery.pdf
https://www.mdpi.com/1996-1073/11/9/2191/pdf

So the cobalt based ones have oxygen loosely attached, and when hot, can cause combustion. This makes it more hot, and thermal runaway goes nuts! And LiFePO4 does not have this problem, no cobalt. Am I missing something?

And this is what combustion is: high-temperature exothermic redox chemical reaction between a fuel and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combustion in a fire produces a flame, and the heat produced can make combustion self-sustaining. LiFePO4 heat generation, is not self-sustaining, and does not create enough heat to combust cells next to it.

It will create heat, but not much. There is no "cascade" effect, from what I can tell. It is not considered a oxide based lithium ion chemistry. And I remember when learning about rocket fuels (scott manley's youtube channel!), that pressure and temperature have a huge part to play in this reaction.

But what I find interesting is the thermal runaway properties of LiFePO4 at various temperatures... it does not increase. View attachment 1340

And simpli-phi, which creates high quality, UL listed battery packs, states this as well:
View attachment 1342

Technically, any battery can pose a fire threat because it can cause a conductor in a system to heat up (if OCPD not present), and set something else on fire. But the internal chemistry of a lifepo4, as I can tell and what safety studies have shown, is that it cannot. If you disagree with this, please let me know below.

Not real familiar how to post, but thought this would be good to share. Ive been adding solar and building battery banks for the past year. I am a commercial electrician but the battery building is new territory. I has this 310AH 16s battery operating just fine with an Ant BMS. Luckily had it in a metal box and in the garage. Ive had no issues, solar charges during the day, battery at night. I cycle pretty low (I think) I stop charging at 54V and Start back up at 51.2V. The inverter was still operating while she was smoking. I dindt have a temp sensor on this specific cell, so it just cooked. I can not for sure identify what caused it. Im hoping to blame myself as I would like to use the other 15 cells. But concerned it was an internal cell failure. Has anyone experienced this?

 

[rhino]

Not real familiar how to post, but thought this would be good to share. Ive been adding solar and building battery banks for the past year. I am a commercial electrician but the battery building is new territory. I has this 310AH 16s battery operating just fine with an Ant BMS. Luckily had it in a metal box and in the garage. Ive had no issues, solar charges during the day, battery at night. I cycle pretty low (I think) I stop charging at 54V and Start back up at 51.2V. The inverter was still operating while she was smoking. I dindt have a temp sensor on this specific cell, so it just cooked. I can not for sure identify what caused it. Im hoping to blame myself as I would like to use the other 15 cells. But concerned it was an internal cell failure. Has anyone experienced this?

Would be helpful if you posted this as a new message in the https://diysolarforum.com/forums/up-in-smoke-learn-from-my-mistake.83/ forum so it doesn't get muddled up in this thread.

 

[jhooligan65]

Would be helpful if you posted this as a new message in the https://diysolarforum.com/forums/up-in-smoke-learn-from-my-mistake.83/ forum so it doesn't get muddled up in this thread.

Thanks! I actually did. Found this via Google and didnt realize it was from 2019!

 

[Will Prowse]

It is impossible to have a self propagating thermal runaway with lifepo4. You can catch it on fire like wood, and the electrolyte will burn. But that's not thermal runaway

 

[jhooligan65]

It is impossible to have a self propagating thermal runaway with lifepo4. You can catch it on fire like wood, and the electrolyte will burn. But that's not thermal runaway

Any thoughts or experience on how something like this could happen? Loose terminal? BMS? Bad Cell? I actually bought the cells and Ant BMS from watching your videos! Thanks for all you do.

 

[timselectric]

It had to have been a loose connection or a short circuit.

 

[jhooligan65]

It had to have been a loose connection or a short circuit.

Loose connection is what I am leaning towards. I dont see how it could have short circuited unless the case broke, or internal short in the battery?

 

[timselectric]

If two cells made contact with the case, it would be a dead short of whatever the voltage is between those two cells, in the series string.

 

[Bob B]

If two cells made contact with the case, it would be a dead short of whatever the voltage is between those two cells, in the series string.

There's voltage on the case, but I have seen tests that show it is very low leakage current. It's not a direct short to either terminal.

 

[timselectric]

The case is directly connected to one of the poles. I can't remember which, I want to say negative.

 

[timselectric]

That's why they are wrapped in shrink wrap. And also the reason for placing insulators between.

 

[timselectric]

The case is directly connected to one of the poles. I can't remember which, I want to say negative.

Just checked, it's actually the positive.

 

[chess-equality]

If I have a parallel battery bank sitting in storage, any chances that a battery / BMS will fail and cause a dead short under normal circumstances, with the pack doing essentially nothing?

 

[32 volt boater]

Can someone prove to me that proper acceleration when the traffic light turns green wastes fuel?

That myth that hard acceleration wastes fuel is left over from the days of carburetors but everyone still believes it so you miss the damn left turn arrow and have to wait two light cycles because people won't move.

Oh ya sure slow acceleration saves fuel, next tell me filling a bucket slowly uses less water.

Myths are real tough to bust.