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Re:Gigafactories are recycling old EV batteries into new ones by scythe on Sunday October 30, 2022 @10:59AM (#33395011)
>LFP (lithium iron phosphate) batteries are already used by Tesla and have a gravimetric energy density of 125 Wh/kg, much lower than Lithium-ion.

Tesla uses iron phosphate in its cheaper models, but the high end is still reliant on NMC. I'd be interested to know the maximum range available on LFP.

BYD sells a lithium-iron-phosphate battery with an energy density of 150 Wh/kg. CATL's LFP is 125.

Also, a lithium-iron-phosphate battery is a lithium-ion battery, in that the electrolyte works by lithium ionic conduction. The appropriate contrast would be "lithium-nickel".

>CATL currently produces a sodium-ion battery at 160 Wh/kg, and they expect the next generation to reach 200 Wh/kg.

This is reported as the "single-cell" energy density, and is not directly comparable to the battery pack density.

>Now consider that sodium-ion is less flammable and doesn't have the risk of thermal runaway.

Surely this isn't because of the stability of sodium, which anyone who watched that chemistry demonstration in high school knows, is significantly more reactive than lithium. I expect the risks to be similar; furthermore, the concept of a dense energy storage that has no risk of sudden release is physically unlikely.

Re:Gigafactories are recycling old EV batteries into new ones by quonn on Sunday October 30, 2022 @11:39AM (#33395372)
> Tesla uses iron phosphate in its cheaper models, but the high end is still reliant on NMC. I'd be interested to know the maximum range available on LFP.

In theory 490 km, in practice, 380 km. Because they don't degrade as much, after a few years they are closer to what you call the high end models.

Re:Gigafactories are recycling old EV batteries into new ones by samatman on Sunday October 30, 2022 @12:01PM (#33395589)
> Also, a lithium-iron-phosphate battery is a lithium-ion battery, in that the electrolyte works by lithium ionic conduction. The appropriate contrast would be "lithium-nickel".

Correct, I want to point out that John Goodenough was responsible for the basic research which lead to all lithium-ion batteries.

I explicitly intended LiFePO to be included, and I hope for a variety of reasons that it's much more popular than cobalt-heavy formulas in ten years.

Re:Gigafactories are recycling old EV batteries into new ones by ben_w on Sunday October 30, 2022 @12:15PM (#33395720)
Only now do I realise that "Goodenough" is a real person's name, and neither a placeholder name nor a case of Emphasis Via Capital Letters:

https://en.wikipedia.org/wiki/John_B._Goodenough

Re:Gigafactories are recycling old EV batteries into new ones by scythe on Sunday October 30, 2022 @12:49PM (#33396060)
I have been interested in the technology from TexPower:

https://texpowerev.com/

They offer a lithium-nickel chemistry without cobalt. If it can be proven in practice, it would allow comparable density to the best car batteries in a scalable chemistry. The founder is a researcher at the University of Texas who wrote several papers on the chemistry:

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.2020027...

https://www.sciencedirect.com/science/article/pii/S240582972...

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/aenm.2...