Can LiFePO4 Batteries Combust in Thermal Runaway Event?

[timselectric]

Just double checked, to be sure I wasn't mistaken.
I was, it's the negative. (It is after midnight)

edit: Actually just checked again and it is actually the positive. I'm too tired to think, Goodnight.

 

[32 volt boater]

Oh /nevermind those video posted already.

This is cool

 

[jhooligan65]

Just double checked, to be sure I wasn't mistaken.
I was, it's the negative. (It is after midnight)

edit: Actually just checked again and it is actually the positive. I'm too tired to think, Goodnight.

Lol. Thanks for the help. If nothing else it got me in the forums!

 

[wattmatters]

Are the cells rated to be installed in that orientation?

 

[timselectric]

Are the cells rated to be installed in that orientation?

They look like EVE cells, or very similar.
So, I would think yes.

 

[Goboatingnow]

The LFP out gas isn’t flammable. LFP do not suffer thermal runaway.

There as safe as any high capacity battery can be.

 

[740GLE]

Oh /nevermind those video posted already.

This is cool

This one is slightly better, sadly uncle Rodney doesn’t show up under full revs of glory.

 

[RV10flyer]

There is 4500 Ohms resistance between pos terminal and alum case. That produces 711 micro amps of current flow at 3.2V.

Edit: I did an actual continuity test. See results below. Sorry, I was using a formula after taking a resistance measurement. Then I thought, I'll just get my meter out.

 

[timselectric]

There is 4500 Ohms resistance between pos terminal and alum case. That produces 711 micro amps of current flow at 3.2V.

Voltage in this scenario would be dependent on how many cells were between two cells making contact with the case. And would heat lower the resistance to allow more current to flow?

 

[RV10flyer]

I just tested one of my eve cells from negative terminal to the case and measured 1.2mA of current flow. 19.2mA if we went with all 16 cells or 53.3V -typical for me. My old JK draws 10mA. Our new JK draws 14mA. Of course if you have the LCD, add another 29mA. That gives you an idea of how much current can flow between the negative terminal and the case. I insulate mine with polyamide tape, ceramic fiber cloth.

*Interesting...I tested a second EVE 280 cell: 3.8mA from neg term to case. Tested my Energetech Fortune 100aH cell neg term to case: 0.60mA!!!

Measured with my Fluke work meter.

 

[Msg43]

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.

@Will Prowse Thanks for everything you do! You are an amazing resource to me!

What do you make of this statement from Relion: "In extremely rare critical failure scenarios (i.e. severe physical damage from a crash or abuse of the battery in extreme applications for which it was not intended) LiFePO4 batteries may experience a thermal runaway event. During a thermal runaway event individual cells vent gasses as a failsafe to reduce the chance of conflagration and or spontaneous disassembly of the entire battery."

Source:

https://ceb8596f236225acd007-8e95328c173a04ed694af83ee4e24c15.ssl.cf5.rackcdn.com/docs/product/Relion_SafetyLithiumBattery_Jan2021.pdf

REDUCE the chance of fire or explosion doesn't seem to mean zero.

Thanks,
Matt

 

[timselectric]

After reviewing the pictures again. All of the terminals on the left side are very close to making contact.

 

[Will Prowse]

@Will Prowse Thanks for everything you do! You are an amazing resource to me!

What do you make of this statement from Relion: "In extremely rare critical failure scenarios (i.e. severe physical damage from a crash or abuse of the battery in extreme applications for which it was not intended) LiFePO4 batteries may experience a thermal runaway event. During a thermal runaway event individual cells vent gasses as a failsafe to reduce the chance of conflagration and or spontaneous disassembly of the entire battery."

Source:

https://ceb8596f236225acd007-8e95328c173a04ed694af83ee4e24c15.ssl.cf5.rackcdn.com/docs/product/Relion_SafetyLithiumBattery_Jan2021.pdf

REDUCE the chance of fire or explosion doesn't seem to mean zero.

Thanks,
Matt

If you hold it over an open fire or have a heat source, or another cell feeding into a shorted cell, it can burn. Just like a stack of wood. But self propagating thermal run away with lifepo4 is simply impossible. The electrolyte can burn and they will mistakingly term it thermal runaway, but it's very different than thermal runaway with a cobalt based chemistry where oxygen is released and reacts with constituents in the cell causing more heat and more heat etc.

 

[Will Prowse]

Check out this picture. Lifepo4 is flat line on bottom because it is not self propagating. It's quite literally impossible due to its materials:

They need to stop calling it runaway when it's not self propagating. They should say it's combustible, like wood. Or many other things once it reaches a certain temperature in this oxygen rich planet.

 

[Msg43]

Check out this picture. Lifepo4 is flat line on bottom because it is not self propagating. It's quite literally impossible due to its materials:
View attachment 112124
They need to stop calling it runaway when it's not self propagating. They should say it's combustible, like wood. Or many other things once it reaches a certain temperature in this oxygen rich planet.

I 100% agree with you. I was very surprised that a BATTERY MAKER would use the term so loosely when it really means something different!

 

[Bob B]

Just checked, it's actually the positive.

So ... put a resistor between the case and the negative terminal and see how much current you get.

 

[Bob B]

I just tested one of my eve cells from negative terminal to the case and measured 1.2mA of current flow. 19.2mA if we went with all 16 cells or 53.3V -typical for me. My old JK draws 10mA. Our new JK draws 14mA. Of course if you have the LCD, add another 29mA. That gives you an idea of how much current can flow between the negative terminal and the case. I insulate mine with polyamide tape, ceramic fiber cloth.

*Interesting...I tested a second EVE 280 cell: 3.8mA from neg term to case. Tested my Energetech Fortune 100aH cell neg term to case: 0.60mA!!!

Measured with my Fluke work meter.

So ....NOT a direct connection to the battery terminal?

 

[RV10flyer]

So ....NOT a direct connection to the battery terminal?

Oh yes, the case is connected somehow, with a very high resistance to the positive terminal. More or less so on each individual cell. If you put a wire from the alim case to the cell negative terminal, it will conduct the above numbers I mentioned. It doesn't produce any measurable heat, but it would drain your cells if you put the cells in a metal compartment that connected to the neg terminal of battery or car or ebike or tractor or airplane....and you wore a hole through the thin blue plastic. A good reason to insulate between cells and around all of the cells once your battery is complete, especially in her mobile application.

 

[Gazoo]

Oh yes, the case is connected somehow, with a very high resistance to the positive terminal.

I don't think it is. We have been through this many times before and I believe it's leakage current at least with the EVE cells. But I also think there are certain scenarios that could cause problems and it's good to put insulation between the cells especially in a mobile environment.

In the spec sheets one of the manufacturers state the "cans" are not to touch each other. I don't recall off hand which manufacturer that was. Best practice is to keep cells insulated from each other and any metal fixture and keep the cells mounted upright if possible.

 

[RV10flyer]

I don't think it is. We have been through this many times before and I believe it's leakage current at least with the EVE cells. But I also think there are certain scenarios that could cause problems and it's good to put insulation between the cells especially in a mobile environment.

In the spec sheets one of the manufacturers state the "cans" are not to touch each other. I don't recall off hand which manufacturer that was. Best practice is to keep cells insulated from each other and any metal fixture and keep the cells mounted upright if possible.

I wouldn't have believed it either until I grabbed a meter. Set it to milliamps, move your red test lead over to measure milliamps and it will show you how much current is being conducted from the alum case to the negative terminal on the cell. Yes, I would understand it's not a wire, but possibly the lithium salts/electrolyte that is not insulated from the case. Just guessing, because every cell is slightly different.