this post was submitted on 20 Jan 2024
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Electric Vehicles
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I don't understand why EV use Li-ion or Li-po in the first place. LiFePo is clearly a superior choice for something like an EV.
One of the biggest challenges with mass EV battery production is making sure performance stays somewhat flat across the entire market you're selling them in. Typically, LiFePo batteries perform better at higher temperatures than other chemistries, at the expense of low-temperature performance.
This works well, as long as
#1 is much easier to enforce as a manufacturer, but customers will be pissed if they move north, and their vehicle has worse range and power.
Li-ion has a flatter temp/performance curve, so it's more suited to geographically larger markets like the US, where regulations require a single range number for the entire country, despite the significant climate variance
This can be mitigated greatly with heat pumps and insulation around the cells.
But the model 3 standard range has LiFePo cells and it's fine in cold climates. On top of this it doesn't have to heat the battery to fast charge.
In the cold the biggest range killer is heating the cabin not the cells. Optimal cell temp is 0-45 and this can be taken off the motors if the car is pushing that range with assistance from a heat pump.
Car makers have sold trucks in north America that need block heaters to start with no block heaters for ages. I think they just want as big a worthless range number as possible.
Energy density. NMC batteries are ~~50+%~~ better when it comes to energy density so you can pack more energy storing capacity for the same weight
Edit : I read up and my percentage figure is off. I was deriving numbers from some old articles. Currently it seems NMC batteries have around 20℅(? Please correct me if I am wrong again) better energy density.