Sodium batteries for cold weather performance

[binkypoo]

I don't see any companies in the US or Canada marketing ev's specifically geared towards cold climates.

This is a niche someone will eventually exploit, why not be the first?

It's a pretty straight forward sales pitch: most ev's lose roughly 40% of their range in extreme cold like that found in many northern US states and all of Canada.

So that Tesla or whatever other car that normally gets 250 miles on a full charge may only go ~150 in cold weather.

Meanwhile CATL, the world's largest battery manufacturer has very recently released a sodium battery option that would only lose maybe 10% range in the same scenario as above leaving you with 225 miles of range on the same full charge.

These batteries are less expensive to build and last longer as well but that's just an afterthought.

Couple with awd and the ads would write themselves.

A bad ass AWD slate truck barreling through the snow that is largely unaffected by cold would crush it in Canada and the cooler bits of the US...

 

[KevinRS]

Sodium batteries may be in the future, but that's still where they are, the future.
Also charge density is lower, so you start with an even lower base range.
Where NMC gets 240-350 wh/kg, and LFP 140-190 these new CATL Sodium apparently get 200, lose 10% and you are down to 180. A lot of that cold advantage goes away because you have a lower base capacity, and if you are driving where it's warm, you still don't have that base capacity.

Lithium based batteries have also gotten a lot cheaper with manufacturing scaling.
In a few years, once manufacturing is scaled up, Sodium may be enough cheaper to buy that we will start seeing the in more places, but looking at range on cars is probably the wrong place to look. AWD needing more power means the range is even shorter.

It may well be that they will be seen in city cars in the future, but not likely in anything where range is a concern.

 

[phidauex]

Sodium ion batteries are promising, and the wide operating temperature ranges are very appealing for many applications.

I think there are two problems for the moment -

1. Energy density is still lower than you'd want for an American EV - we have much larger range expectations than most global markets. You might be at the point where a 150-180mi range battery could be put in many platforms, but with the weight of the extended range. For the Slate that might land you at 130-140 miles, which I don't think would sell well, even taking the temperature stability into account.
2. No US manufacturers yet. You'd be crazy to build your product around a Chinese cell right now with the current political and tariff situation.

With time there will be manufacturing and density improvements, and eventually US or at least north america manufacturing, but I wouldn't expect to see Sodium Ion (or solid state for that matter) in a production car in the US until the 2030 range.

 

[binkypoo]

Sodium batteries may be in the future, but that's still where they are, the future.
Also charge density is lower, so you start with an even lower base range.
Where NMC gets 240-350 wh/kg, and LFP 140-190 these new CATL Sodium apparently get 200, lose 10% and you are down to 180. A lot of that cold advantage goes away because you have a lower base capacity, and if you are driving where it's warm, you still don't have that base capacity.

Lithium based batteries have also gotten a lot cheaper with manufacturing scaling.
In a few years, once manufacturing is scaled up, Sodium may be enough cheaper to buy that we will start seeing the in more places, but looking at range on cars is probably the wrong place to look. AWD needing more power means the range is even shorter.

It may well be that they will be seen in city cars in the future, but not likely in anything where range is a concern.

An nmc in the cold will have less or equivalent range to the sodium battery at substantially higher cost

So the sodium car could afford to pack a bigger battery in there for the same net cost to the consumer.

But yeah I agree it's not a suggestion for today, it's for the future.

I also agree it's not a solution for every climate, it would be best suited for specific markets where the temperature performance advantages would make it compelling.

Might also be a good fit for hot climates like Arizona as iirc lithium batteries don't like extreme heat either.

 

[KevinRS]

An nmc in the cold will have less or equivalent range to the sodium battery at substantially higher cost

So the sodium car could afford to pack a bigger battery in there for the same net cost to the consumer.

But yeah I agree it's not a suggestion for today, it's for the future.

I also agree it's not a solution for every climate, it would be best suited for specific markets where the temperature performance advantages would make it compelling.

Might also be a good fit for hot climates like Arizona as iirc lithium batteries don't like extreme heat either.

A bigger pack takes more space and weighs more. Potentially Sodium will become cheaper than lithium batteries, but they aren't there yet, and it's not even theoretically going to get more energy dense. The lower energy density is the reason there is less fire hazard after all, energy = energy.

Ok, in certain conditions, cold enough weather, it's possible that the curve of battery mass vs useable capacity will cross, but it's kind of an edge case, and unless you are looking at a low range vehicle anyway, cost of Sodium would have to be Significantly lower for a manufacturer to consider it.

 

[binkypoo]

A bigger pack takes more space and weighs more. Potentially Sodium will become cheaper than lithium batteries, but they aren't there yet, and it's not even theoretically going to get more energy dense. The lower energy density is the reason there is less fire hazard after all, energy = energy.

Ok, in certain conditions, cold enough weather, it's possible that the curve of battery mass vs useable capacity will cross, but it's kind of an edge case, and unless you are looking at a low range vehicle anyway, cost of Sodium would have to be Significantly lower for a manufacturer to consider it.

By your own admission CATL's sodium batteries are roughly on par with the energy density of LFP batteries.

Ford, Tesla, Rivian, GM, Nissan, Stellatis and others are either currently selling cars with LFP batteries or planning to do so in the next couple of years.

So by your logic, those companies are all making cars that cannot possibly compete with NMC, yet they are all either currently or planning to heavily use LFP which will have comparable energy density to sodium but worse performance in extreme cold/heat, fewer charge/recharge cycles, and cost more money on the cell level today, not in some hypothetical future (specifically talking about CATL here).

If it makes sense for Ford to go all in on LFP for their upcoming small ev truck, which will be a direct competitor to Slate but from a huge international brand with deeper pockets and arguably more consumer trust, how will Slate compete?

But hey it's not like either you nor I are making decisions here. This is all just a discussion forum for suggestions

I'd leave it all up to the market and engineers that have a better idea how it would all play out in actual use. If nothing else paying attention to CATL and perhaps demoing some of their sodium battery packs would make sense to see if it either makes sense today or will down the road.

In any event I'd assume there will be massive tariffs on CATL batteries under the current administration so it's probably nothing that would happen until the winds change on that front or someone either licenses the tech to make here in the US or comes up with a competing product here or in a country that won't be heavily tariffed.

I guess my main thesis for the suggestion is: what's a market niche other than the current ones Slate is targeting (cheap, heavily customizable, easily repaired) that are worth considering to give this small company a chance to not just survive but thrive?

 

[KevinRS]

That still hypothetical Ford truck, that so far as we know is still just a platform and a vague plan, will highly likely have a lot more pounds/kilograms of battery than something like the Slate.
Those CATL Sodium batteries are claiming to be on a par with LFP, but it's not something that has been scaled up like lithium yet.
Even then, people here have calculated that an extended Slate battery sized LFP would have around 200 mile range, go with that for your Sodium range, minus 10% for extreme cold, 180. Compare to the 240 mile extended range battery planned, if that 40% drop in range is correct, you have 144. I don't completely trust that 40% drop in range. I think that assumes you are starting with a cold battery. If it's charging, it's warm, if the truck is running, it's warm. Most of that 40% loss may assume you start with a charged battery, but one that's been unplugged all night. If you are somewhere that cold, even on an ICE vehicle, a block heater is often used if parked in the cold.

 

[binkypoo]

That still hypothetical Ford truck, that so far as we know is still just a platform and a vague plan, will highly likely have a lot more pounds/kilograms of battery than something like the Slate.
Those CATL Sodium batteries are claiming to be on a par with LFP, but it's not something that has been scaled up like lithium yet.
Even then, people here have calculated that an extended Slate battery sized LFP would have around 200 mile range, go with that for your Sodium range, minus 10% for extreme cold, 180. Compare to the 240 mile extended range battery planned, if that 40% drop in range is correct, you have 144. I don't completely trust that 40% drop in range. I think that assumes you are starting with a cold battery. If it's charging, it's warm, if the truck is running, it's warm. Most of that 40% loss may assume you start with a charged battery, but one that's been unplugged all night. If you are somewhere that cold, even on an ICE vehicle, a block heater is often used if parked in the cold.

There's so many assumptions in this.

I don't know that a car with a sodium battery 100% by default has to have less range than one with NMC.

Like sure ok, assuming you go with an identical physical size pack, and the cells themselves are identical size, then sure the better energy density of NMC will provide better range under normal conditions. But in that case the Sodium car will cost dramatically less.

Sodium is already and will be so much cheaper than NMC that you can use a larger pack to get the same range at less total cost. It's already something like 30% cheaper than LFP on the cell level and it's only just now going into production.

Bear in mind LFP cells are substantially cheaper than NMC which is what Slate is using.

I do agree 100% the current CATL sodium battery is nascent for sure. This is not a today suggestion. More of a 1-2 years from now suggestion.

As for the range loss info, it comes from a study in Norway where most ev's lost around 40% of their normal range, and some lost closer to 50%. The Norwegian page: https://www.motor.no/bil/rekkeviddetesten-vinteren-2026/344177

An English language article summarizing the results: https://insideevs.com/news/785827/winter-extreme-cold-range-test-el-prix-2026/

Feel free to pick apart the methodology.

 

[AZFox]

The lower energy density is the reason there is less fire hazard after all, energy = energy.

When I look it up it appears that NMC cells' electrolyte is highly flammable and sodium-ion batteries use non-flammable electrolytes.

Then again, there was on-the-fly AI "research" involved, so...

 

[phidauex]

While LFP chemistry is slightly safer than NMC, and NaIon should be slightly better than LFP, in practice the biggest difference is in manufacturing quality (and certain elements of the cell design and packaging). Any stored energy device can start a fire, and even a theoretical magical battery with 0 flammability would still be able to short circuit and light everything else around it on fire.

I operate many GWhs of batteries of several chemistries right now and we have NMC batteries that have never seen a single thermal runaway (outside of a directed test), and we have LFP batteries that have failed in their enclosures and gone into thermal runaway. My view is that a good manufacturer can make a safe battery out of multiple chemistries, and a bad manufacturer will make a dangerous battery regardless of their chemistry choice.

 

[beatle]

This isn't anything technical on sodium/LFP/NMC benefits/tradeoffs, but keep in mind that Slate has a contract with SK On to build their batteries. SK On isn't even building LFP batteries at scale in GA yet, much less sodium.

The need for an energy dense battery like NMC is even more pronounced in a small chassis if you need to hit a "reasonable" range target like 230-240 miles. The Slate is small, and even with a purpose-built EV platform and no substantial utilitarian reason to keep the truck lightweight, you just can't crack 200 miles of range without using NMC.

With that SK On contract in mind, I think it's more likely we'll see LFP in the Slate before we see sodium. When LFP comes online in GA, I could see Slate pivoting to that. In theory they can just do a chemistry change for the standard pack cells so the case and cooling can be largely the same, though this is really just armchair engineering.

Re: Sodium, I heard in some interview (maybe Barman or Scaringe?) that manufacturers wish they could be more nimble WRT new battery technologies. Even Tesla who pours money into R&D has struggled to extract value from their tabless 4680s for the past 6 years. Only recently have they started to really ramp that up as a viable asset.

 

[phidauex]

Exactly, it takes a long time to get a new cell line up and running, and then to get it up to scale. And even then you have to compete with everyone else who wants to buy up all the manufacturing slots. I'm generally in favor of making things in the US, but this is an example of where we've really painted ourselves into a corner with the trade war, and things like advancements in battery technology will come to the US 3-5 years after they arrive anywhere else. This doesn't just impact batteries, but most forms of advanced manufacturing and products that require a lot of scale up rather than small batch production.

 

[rmay635703]

Sodium batteries may be in the future, but that's still where they are, the future.
Also charge density is lower, so you start with an even lower base range.
Where NMC gets 240-350 wh/kg, and LFP 140-190 these new CATL Sodium apparently get 200, lose 10% and you are down to 180. A lot of that cold advantage goes away because you have a lower base capacity, and if you are driving where it's warm, you

Your numbers are off because of “packaged density “
You can cut cell density in half or more for lithium “as installed “ due to the weight of armor and cooling systems required to safely use lithium in a vehicle.
Sodium does not require the complex cooling or heating fins, it also can be punctured without fire reducing the weight of packaging/armor.

Once you account for this the weight difference of sodium vrs even high end lithium narrows dramatically and the cost difference grows.

sodium batteries are already in EVs and PHEVs overseas, so “in the future “ is only true in NA. Everywhere else they exist in the low end.

1 Prius battery replacement company uses nexcell sodium ion in US packs.
So sodium is technically available here as well.

until the cells grow in reliability they stay as science experiments but they really should be available as industry standard T105 golf cart deep cycle battery replacements today as cost should actually be lower than FLA and all sorts of solar and hobbiest equipment uses those standard batteries.

 

[beatle]

I think you're overstating the benefits of sodium's savings on cooling, heating, and armor needs. They're better in cold weather, sure, and you don't have to heat them (another bonus for energy savings) but they still need cooling. This is especially needed when fast charging or when the battery is dumping current to accelerate quickly, like a loaded truck going up a hill. To simplify, having a sodium battery would be like having the year round capacity of an LFP battery in Texas or Arizona - but also in Maine.

The pack still needs armor to protect the cells from running over a rock or other hazards. It's just nice that it's less bad if/when that armor is breached.

Don't get me wrong, though. By the spec sheet, I think sodium is probably a good successor to LFP for its presumed durability, performance consistency in all temps, and lower risk profile, but it's still pretty new, and I don't think it's a miracle.

Cold range EV loss also isn't 40%, and what range you do lose is not all because the battery is cold. Cold air is denser and requires more energy to push through it, and HVAC demands in cold temps, even with a heat pump, are higher than that of A/C in high temps. This is exacerbated in short trips where people often collect data, like their commutes. Some examples I observed in my R1T:

I used almost 11% on my way to work when it was 13 degrees out. The same trip in early October at 59 degrees takes 4%. This is pretty consistent with last winter's performance. Long trips are still fine in the cold. For comparison, I make a ~200 mile trip to see my family a couple times a year. These are both with almost no traffic, clear skies, calm wind.

At 36F, the trip consumes 72% battery
At 74F, the trip consumes 64% battery

 

[Johnologue]

When I look it up it appears that NMC cells' electrolyte is highly flammable and sodium-ion batteries use non-flammable electrolytes.

Then again, there was on-the-fly AI "research" involved, so...

IIRC, the safety advantage is either limited or mostly-limited to "aqueous" sodium-ion batteries, which also have the more significant disadvantage on energy density. So, the non-aqueous ones being used for automotive traction batteries are probably similar to lithium-ion/NMC in terms of safety.