Comment by rule2025
17 hours ago
Lithium iron phosphate batteries are very practical. Chinese BYD has developed blade batteries using this type of battery and has become the global sales leader in new energy vehicles. However, this battery faces range limitations and the issue of how to improve charging speed. Solid-state batteries should be the next big thing, but mass production may not be feasible yet. At least, it might take 3 more years for commercialization, and that's still an optimistic prediction.
> 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).
> 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.
> LFP charging in cold has pretty much been solved by adding a heater to battery pack.
That's a hack, not a solution.
> Given CATL is scaling sodium-ion production to to GWh scale next year, it sounds like they are betting for a much shorter timeframe.
Wanna bet? LFP is ~1,000 GWh scale right now. GWh scale is 0.1%.
11 replies →
Does the heater handle real winters, like they have in Alaska, Mongolia, and parts of Russia north of it? Or just European and American "winters" where -20°C is considered hardcore? Gasoline powered engines handle this well, and you can warm them up with a gasoline torch if they stay outside for too long and refuse to start. The cold does not destroy them.
13 replies →
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.
One thing I hadn't groked about Sodium Ion was the enormous Voltage range leads to a bit of an issue when it comes to current. You have a 4x voltage from top to bottom of the battery and this also means your current is 4x as well for the same power output. This becomes a bit of an issue and it is part of the efficiency equation, not just externally to the battery where wires have to be much larger than LFP or LI but internally due to internal resistance.
Sodium gravimetric density is same. Volumetric is worse. Shipping containers generally cost by volume, but given how dense batteries are I suspect this won't matter.
1 reply →
> 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
such strange unit of measurement. cubic feet of space. especially for civilian transport when most of the time no one uses that space. i mean most of the time its one person per car without any baggage. what's important is weight of the car. and i bet suv is heavier than sedans.
1 reply →
There are variants of the Model Y with LFP batteries.
I've tried to express SUV's as in American SUVs - full sized 7 seat monstrosity. Most EV SUVs right now are crossovers, i.e. Model Y. Cybertruck is closest approximation and it uses nearly 2x more power than Model Y. Even with ~most advanced batteries people still think Cybertruck's range is way too little whereas I'm pretty certain majority of Model Y's sold are LFPs.
1 reply →
What? How does an SUV require less power per cf than a sedan? I would think that aero alone would always be worse for an SUV, making sedans more efficient.
3 replies →
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.
Using lfp at low temp is not an issue. Charging is the problem.
1 reply →
> Unless you want to charge in negative temperatures
Doesn’t the thermal management system of the battery packs handle this?
Yes, the largest issue is that they heating isn't enabled unless it's charging or 'knows' it will be soon.
Ps: the heating is increasingly heat pump based instead of resistive.
It does, but it costs is complex, requires power and time.
It's noticeable even in climates like NZ.
There are coldgating stories about LFP. Some even reduce output and very low SOC and temperature, so you drive 60km/h in highway.
Sodium is vastly superior here and CATL is not going to be giving it away for free.
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.
When are the aluminum batteries coming?
It still does have expensive materials (cheaper form of graphite), but a little bit less of it, namely lithium and there's something else I can't remember.
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.
Solid state batteries and fusion power, always 3 years away.
I wouldn't equate solid state batteries with fusion power. Solid state batteries do exist and work well, they are just very expensive. Meanwhile fusion power is still entirely within the experimental stage and there are no fusion plant prototypes that can produce power at any price.
It’s always 20 years away until it isn’t. Self driving cars are…I guess they are here already. AGI? Well, we have to move the goal post on that constantly.
Self driving cars have had many incremental improvements. I think fusion power is actually making progress, not clear about solid state batteries. Seems more companies closing than making solid progress.
2 replies →
>Self driving cars are…I guess they are here already.
They may be where you are, but they aren't generally here.
8 replies →
Add Affordable at the start of that sentence and it's accurate.
Solid state batteries seem to work, but the price of prototypes is very high. Samsung says they will soon be shipping earbuds and watches with solid state batteries, but the cost is too high even for phones. Xaomi showed an $800 phone battery. Mercedes has one prototype car with solid state batteries. Honda has one motorcycle. EHang has one flying car. Nobody seems to be past one-off demos.
Solid state batteries and fusion might in the end suffer from a similar economical problem. That they turn out to simply be too expensive.
Does look as if ssb are close.. Esp Japanese ones.
If your source on that is a Toyota press release, take it with a huge grain of (lithium) salt.
Toyota has been saying similar things for a very long time. But they continue to make extremely poor bets, except for their hybrids. There's something really odd about their management culture that prevents them from finding the common and easy path of lithium ion batteries that everybody has already taken.
6 replies →