What are the barriers to moving to LiFePO4 for these large scale facilities? My understanding of them is that they're much harder to ignite, even when there's a charging fault. I'm not sure if there's a big energy or power density difference though.
The biggest barrier has been patents and availability. A number of patents expired this year, so I'm expecting a lot of new players and locations to get into LFP production very quickly.
LFP for home or grid storage is a nearly no-brainer compared to other chemistries since it's so much more stable and has much better aging and cycle characteristics. The slight loss of power density doesn't matter for stationary installations.
Longer lasting (in both calendar life and charge cycle count)
Safer - can tolerate higher temperature, does not catch fire if punctured (e.g. by a bullet)
Cheaper
Less toxic than 'legacy' lithium-ion (also known as NMC, nickel-manganese-cobalt, and NMCA, NMC + aluminum chemistries)
Slightly more tolerant of abuse (overcharging and overdischarging).
Less stored energy per pound/kilogram, by 20% - 30%, than 'legacy' Li-ion so perceived as less suitable for cars, although Tesla uses it in Model 3 except the long range version.
Big manufacturer: CATL, a Chinese firm, who bought the key patents 20-odd years ago. Patents expire this year.
LiFePO4 = lithium iron phosphate. Iron and phosphate are cheap and abundant compared to the nickel and cobalt used in 'legacy' lithium-ion batteries, and come with fewer "high horse" concerns (child labor, de-facto slavery in the Democratic Republic of the Congo's cobalt mines, environmental damage, nickel comes from Russia, etc.) (Fun fact: there's a lot more nickel in a 'lithium' battery than there is lithium.)
As well as Li, Fe, and PO4, LFP also uses carbon nanotubes apparently.
- Less energy dense than lithium ion
+ Safer/stable chemistry (not prone to thermal runway)
+ Drop in replacement for lead acid, which allows you to use it with the vast array of 12V/24V/48V equipment.
If you're not constrained on weight/size, I see no reason not to choose LFP for stationary uses.
There was a fire at a similar Tesla grid-storage battery facility in Victoria, Australia, in 2021. EEVBlog covered it in a couple of videos, with the post mortem here:
> TLDR; The megapack was taken offline at the time of the fault, so it was not charging or discharging. A leak in the cooling system caused a short circuit in some component that started the fire. So the power to sustain the short and subsequent fire must have come from the internal pack.
Also, offline mode disabled all protection systems and monitoring communications, so they had no way of knowing anything was wrong until someone yelled fire.
