alt Hacker News> Lithium iron phosphate batteries are very practical
Unless you want to charge in negative temperatures
> However, this battery faces range limitations
Yes they are less dense but plentiful for typical passenger car (and not so much for full sized trucks or even "mid-sized" US SUVs).
> the issue of how to improve charging speed
I think CATL demonstrated 1MW charging on these already. Definitely shipping 500kW charging (tho best measure is still average km/hr).
> Solid-state batteries should be the next big thing
Sodium will (great cold weather performance and even better charge rates), but it's less (vol) dense and prices won't reach LFPs for another 10-15 years (unless you believe hype, not actual analysts).
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The small handful of sodium batteries that are currently available retail all seem to have rather bad roundtrip efficiency compared to LFP and voltage drop starting at a high state of charge.
Also LFP prices dropped enough that shipping cost from China became a significant part of the price. This will be even more of a factor should the less energy dense sodium batteries ever reach the promised $30/kWh.
> Unless you want to charge in negative temperatures
I do all of my charging way above 0K. :-P
If it's suitable for sedans it's actually more suitable for SUVs. SUVs require less power per cubic feet of space. So there is more space available for them, even if they take more energy overall
I think CATL is promoting a hybrid pack of LFP and Sodium that would give you the cheapness and density of LFP, but with maybe 30% Sodium that you could use for a quick partial charge, and could also be used when the car is cold-soaked. Once you drive for a while, the whole pack gets warmed up and you can use the LFP.
> Unless you want to charge in negative temperatures
Doesn’t the thermal management system of the battery packs handle this?
I think it is fairly likely that sodium catches LFP in the ~5 year timeframe since sodium has a lot more promise for grid scale storage since it has no expensive materials.
I am not sure honestly about the negative temperature. Sure it can be a problem in extreme colds but most of the world does not live in those climates.
The issue I’ve heard with sodium-ion is that the voltage curves make the power electronics much more expensive for a given efficiency/power level.
[https://www.eevblog.com/forum/projects/sodium-ion-battery-ev...]
Lithium’s curve is nearly flat, which allows for a pretty easy consistent power production (albeit nearly impossible to tell state of charge!) since you only need to target a pretty narrow voltage band.
Overall, that means sodium-ion has to be even cheaper to be competitive, and it makes even less sense in areas where power density matters like electric cars, as you’ll end up with far less power and/or needing much heavier motors and more expensive electronics to compensate when on the lower end of charge.
I don’t want to think of what it would cost to do a 100kw buck-boost power supply that can handle +- 25% (or more!) voltage differences. In reality, I don’t think anyone would try.
> Unless you want to charge in negative temperatures
LFP charging in cold has pretty much been solved by adding a heater to battery pack.
> (Sodium-ion) prices won't reach LFPs for another 10-15 years (unless you believe hype, not actual analysts).
Given CATL is scaling sodium-ion production to to GWh scale next year, it sounds like they are betting for a much shorter timeframe.