Comment by gamblor956
3 years ago
I hate defending Tesla/Musk, but the reason the new batteries have worse energy density is because they switched chemistries to much cheaper, longer-lived, and safer lithium-iron-phosphate batteries.
The downside to LFP batteries is that they are less energy dense than the old NMC chemistry, though modern LFP batteries now have the same energy density as NMC batteries from about 10-15 years ago (due to the fact that individual cells can be placed more closely together than in NMC batteries due to the lack of thermal runaway risks).
Also as I understand the newer batteries doesn't have cobalt from Congo mined with child slavery. So that is a big plus.
That's not the case for their new batteries:
> Moreover, independent 4680 battery teardowns and chemistry analysis shows that Tesla is still using the regular 811 nickel-manganese-cobalt mixture for the cathodes and ordinary graphite anodes.
https://www.notebookcheck.net/First-Tesla-4680-battery-teard...
They also aren't using added-silicon anodes yet, which may explain why the energy density is so poor. I'm not sure if they are having trouble working on this, or if they are waiting on patents to expire.
Thank you, but also sadface.
Afaik the LFP batteries Tesla uses are from CATL, their own batteries are still NCM