this post was submitted on 27 Dec 2023
103 points (81.6% liked)

RealTesla

477 readers
1 users here now

  1. Posts must be about Tesla, EV, or AV
  2. Meta Posts must be pre-approved.
  3. Shitposts are limited
  4. No Elon Worship
  5. All Links must include the original title of the Content
  6. Sites behind Paywalls must have text included.
  7. Don't be an asshole
  8. No Image Posts

founded 1 year ago
MODERATORS
 

A new crash recently in Alabama, but a reminder to something that we all know. Burning Teslas are far more difficult to extinguish than any other car.

you are viewing a single comment's thread
view the rest of the comments
[–] Nomecks@lemmy.ca -3 points 10 months ago* (last edited 10 months ago) (1 children)

It's not self oxidizing. Old lithium cobalt oxide batteries were, lithium iron phosphate batteries aren't.

[–] GetriFriedRisa@startrek.website 10 points 10 months ago (1 children)

Phosphate will decompose into phosphate ions and oxygen given enough energy. The energy of the P--O bond is greater than Co--O but ultimately means that LFP batteries are also self-oxidizing but less so than lithium cobalt oxide

Reference

  1. Nature of PO Bonds in Phosphates Benjamin Gamoke, Diane Neff, and Jack Simons The Journal of Physical Chemistry A 2009 113 (19), 5677-5684
[–] Nomecks@lemmy.ca 1 points 10 months ago (1 children)

Find me any proof of any lifepo4 cells having a self-oxidizing event. Spoiler alert: you can't, because there's no reaction that can happen with lifepo4 that will strip oxygen out of phosphate. UL listed companies sell lifepo4 batteries as non-combustible. I highly recommend looking into modern battery chemistry, becase they're way safer than people think.

[–] GetriFriedRisa@startrek.website 5 points 10 months ago* (last edited 10 months ago) (1 children)

There's plenty of proof in academic literature. FePO4 is quite stable because of the quirks in iron's valance up to about 500C. But the combination of of lithium skews the valance effects at high temperatures to start losing oxygen at 250C.

Please review the following literature for more information:

  1. C. Delacourt, P. Poizot, J-.M. Tarascon, and C. Masquelier, Nat Mater., 4, 254 (2005).
  2. J.L Dodd, R. Yazami, and B. Fultz, Electrochem. Solid-State Let., 9, A151 (2006).
  3. G. Chen, .XSong, and T. J. Richardson, J. Electrochem. Soc,. 154, 4627 (2007).
[–] Nomecks@lemmy.ca -2 points 10 months ago (1 children)

How much oxygen are we talking here? I'm guessing not much, as they wouldn't be allowed to sell lifepo4 batteries as non combustible if they had any real chance of causing a self sustaining fire. So level with me so I don't have to trudge through a bunch of academic papers: How much oxygen do they mention?

[–] GetriFriedRisa@startrek.website 4 points 10 months ago

The stoichometry comes out with 2:1 moles of lfp to diatomic oxygen which is significant

The combustibility you're referring to is a legal definition not a scientific one