Can LiFePO4 Batteries Combust in Thermal Runaway Event?

[Gazoo]

And if this was the case, wouldn’t all 4 cells be damaged instead of one single cell catastrophic failure ?

Feel free to read through this thread and draw your own conclusions.

 

[A.Justice]

2019 series EVE LF90's have continuity from positive to the case, about 1500 Ω.

TopBand 25ah cells have no continuity on either positive or negative.

 

[Pskel]

How hot are the gasses when LFP vents? Can this ignite wood? Melt aluminum plate? It was hard to t

Feel free to read through this thread and draw your own conclusions.

I’m guessing this is a possibility, thst the blue film wore through somewhere and short circuited… maybe? Cell voltage was 3.4 when it happened and dropped from there. I never blew a single fuse anywhere in the system and none of the wires had any wear or melting exc

 

[Gazoo]

I’m guessing this is a possibility, thst the blue film wore through somewhere and short circuited… maybe? Cell voltage was 3.4 when it happened and dropped from there. I never blew a single fuse anywhere in the system and none of the wires had any wear or melting exc

It is a possibility. Either that or something happened to the cell's terminal due to the lack of proper compression, and that in turn caused an internal short in the cell. Of course it's still possible the cell shorted internally by itself. But I find it odd a cell would short internally by itself after being in service for a year.

I think you have a good understanding of what should be done when you do your next build. Eliminating possibilities for a failure is the best anyone can do.

 

[Daddy Tanuki]

well its fun to speculate on the cause but the most important thing is you are still above ground and breathing air. anything else can be replaced.

Glad to see you unharmed, take care.

 

[offgriddle]

From what I've read and what Will and the other solar gurus say, the technology is safe from self combusting but I I still put my LiFePO4's and associated equipment in and on non flammable enclosures and surfaces. Oorah.

 

[Guna]

I just had a "fb expert" telling me that any lithium can catch fire from thermal runaway. He gave this example but they literally used an external device to overheat the batteries so I don't think that counts. I linked this thread under his comment and told him to come share his genius since he thinks he's such an expert lol.

Thermal runaway and fire behaviors of lithium iron phosphate battery induced by over heating

Lithium ion batteries (LIBs) have been widely used in various electronic devices, but numerous accidents related to LIBs frequently occur due to its f…

www.sciencedirect.com

 

[time2roll]

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

 

[upnorthandpersonal]

From the abstract:

"The cells are over heated using a heating plate. The heating plate is utilized to simulate the abuse process triggered by TR of the adjacent battery in modules." (note: TR = Thermal Runaway).

Yeah, this makes no sense. Let's heat one cell to induce thermal runaway, and pretend this heat is from another cell that went into thermal runaway. Don't matter how that cell got there...

 

[Guna]

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

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

 

[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.