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- Hacker News
- Hardware-speech synthesis.by log-removal
- > a round-trip efficiency of 96 percent
Doesn't matter for cars, but I think that's pretty good/important for grid storage.
by m463 - Series hybrid cars which do fuel->electricity->motion are unacceptably inefficient and flopped at sales. Will sodium make them viable? My reckless googling says LFP batteries in vehicles has roundtrip efficiency of 80% and sodium has 95%.by aitchnyu
- Lithium batteries in cars are usually at least that good already. Most of the efficiency lost is in converting back and forth between AC/DC between the grid and the motors, and the rest in the auxillary features such as heating and cooling the cabin.by zdragnar
- “You need to keep an LFP cell at 25 °C, give or take, or it will rapidly degrade” so LFPs have to be heated and cooled - not difficult to solve but it does add cost and complexity to a battery, something Sodium-Ion doesn't require.
But looking at the discharge profile of Sodium-Ion [1], then a 24v stable output would need about 48v at 100% battery charge and that means cost and complexity on the input and output sides to keep a steady voltage over the discharge cycle. LFP have a much flatter discharge curve but it's a much greater concern with Sodium Ion. Sodium Ion is also criticized for its lifetime cycle degradation.
LTO (Lithium Titanate) batteries hit the sweet spot between both chemistries and are used in electric buses, but I still like Sodium batteries for their environmental considerations.
Wouldn't it be great to somehow harvest power from the temperature swings between night and day in arid regions? Also large changes between sea level and cruising altitude.
I know black tourmaline and certain lithium compounds being pyroelectric generate power upon temperature change due to mechanical stress, which instigates piezoelectricity.
"If the goal is maximum electrical energy generated per degree shift, single-crystal PMN-PT (Lead Magnesium Niobate–Lead Titanate) is currently the top-performing synthetic material." [2]
[1] https://hackaday.com/2025/10/30/why-sodium-ion-batteries-are...
by adrianwaj - LFP’s flat discharge curve is actually kind of annoying: it makes it quite difficult to measure the state of charge of a cell. BMSes mostly need to track the SoC by counting coulombs, and balancing a series of cells may be challenging unless the SoC to reach the steeper part of the curve.
Meanwhile, most serious applications have power conversion circuitry, so a variable voltage may not be much of a problem.
The low-end “12V” LFP packs without real BMSes or power conversion that sort of pretend to be lead-acid batteries in RVs and such are awful designs and work pretty poorly, and their “24V” and “48V” cousins are not much better. It’s true that Na-Ion may not be an easy drop-in replacement. That being said, some people are working on Na-Ion as a lead-acid replacement for car starter batteries (and for low voltage systems in EVs), and they have a lot of potential in this application. (LFP doesn’t have adequate not temperature performance and lead-acid sucks for many reasons.)
by amluto - from what I've heard, the problem with moving sodium from lab to manufacturing is that all the industrial processes and machinery have been setup for lithium and the factories are reluctant to invest in entire new sodium setup for not much benefit for them; lithium works perfectly well and is in fact the superior product, why switch?
Lithium prices have faced a massive crash, so there is no cost penalty for them anymore. Sodium's cost benefit isn't that significant now, and while other technical benefits exist, the question remains, is it worth it to setup an entire new factory from scratch for that marginal benefit?
by ryzvonusef - Sodium batteries use a relatively similar process to lithium, so I'd say overall that has sped up their adoption in manufacturing.
But the economics part is true, people looked to sodium as lithium prices went high and then enthusiasm cooled as they dropped again.
However they now seem to be passed that slump and the long term benefits seem enough for sustained investment.
It helps that the wider market is growing. You can keep your lithium battery factory and use your know how to set up a new sodium battery factory and aim to sell both to slightly different markets for the life of a factory.
by ZeroGravitas - In TFA it said that the US company that was shut down (Natron) pursued a solution quite different from lithium batteries (with an organo-metallic electrode), which may have been a reason for their failure.
On the other hand the 2 Chinese companies that now make sodium batteries "rely on sodium iron pyrophosphate (NFPP) cathodes, which are chemically and structurally similar to lithium-iron phosphate in an LFP battery".
This similarity probably enabled them to reuse much of their existing fabrication lines for LFP batteries.
It is unavoidable that in the long term the cost of sodium batteries will be much lower than of any lithium batteries.
That would have been enough for their adoption for stationary uses, but their much greater temperature range (which allows operation and charging at -40 degrees, both Celsius and Fahrenheit) and their longer lifetime are enough to make them replace lithium batteries in certain applications even without the price advantage.
Lithium batteries will always be used in mobile applications, because they will continue to have a better energy per weight ratio, but for high energy stationary uses and for vehicles in cold climates it is likely that they will be mostly completely replaced by sodium batteries.
by adrian_b - I've been pondering the question of what happens if you change the design requirements to say, 20 charge/discharge cycles in total, then use it over seasonal timescales. Can you get the price so low that you can scale up enough battery storage to buffer a whole season?by hgomersall
- Even if you have an entire season's worth of capacity, your inputs and outputs still cycle per-day. You're still cycling charge and discharge every day, you're just doing it in a very small band within the overall capacity.
This still causes wear on the battery, and it can be better or worse depending on chemistry. The only way to get around that is if you disconnect all inputs, throwing away all the excess solar/wind power and supply exclusively from battery for the entire season.
There's no real benefit apart from like a standby power supply for a cataclysmic event where all other power sources including the sun become nonviable. You just won't ever use the full capacity of the battery, so most of the resources to build it will be wasted.
by vitally3643 - I don't think anyone's cracked that yet. There was a YC startup trying to do stuff with iron oxide. (https://www.canarymedia.com/articles/batteries/gigantic-form...)
And proposals using aluminium but again not in action.
Also zinc air https://inc42.com/startups/sthyr-energy-aims-to-tame-169-bn-...
the trouble is it's easy enough to propose such things but hard to be economically competitive with existing solutions. My guess is sodium ion will get cheap because the ingredients are cheap and there's a lot of money going into mass production which will bring the cost of that down over time.
There's an ancient non electrical seasonal solar storage practiced in Austria and such places where they grow tree and then chop them into logs for the winter but it's a bit labour intensive.
by tim333 - Keep in mind, we could have had local Na-Ion battery production in the US. The company producing them needed about $5m of bridge loans, with products already sitting in warehouses awaiting the UL certification.
This company got sold for scrap.
by cyberax - If it only cost 5M for something like that investors would have been in a line around the building.by parineum
- See also lFP batteries from A123:
> In October 2012, A123 filed for Chapter 11 bankruptcy protection. It was thrown into a narrative of Obama-era green energy failures with defunct California solar company Solyndra that had received hundreds of millions of dollars in federal loan guarantees — a comparison to which Vieau objects because A123's technology was "proven," and it built plants and hired people with government support.
> Wanxiang Group Corp., a subsidiary of the largest auto parts supplier in China, acquired its assets for $256.6 million after it had sought to acquire 80% of A123 earlier that year
by ZeroGravitas - your comment would be more interesting if you actually provided any details at allby petcat
- Given that $5 million is not that much in the heavy industry game, I'd like to know why they couldn't get the bridge loans.
Like, that's not an unreasonable size of loan for a regional expansion for medium-sized businesses; there should be some sort of lender interested in doing that for them.
by lenerdenator - I want to replace my Lithium home battery, and what I really want to do it to move to one of the new sodium ion batteries..e.g like the one CATL is supposed to have at some point?
Anyone have a good idea when these will be available for consumers?
- Why? You also need to replace your inverter in that case.by rapsey
- Why would you replace it? That asset likely has at least 10 years in it if you already have it.by XorNot
- Probably in a year or so. CATL is expecting about 1GWh deployment by the end of the year and has contracts to deliver ~7GWh in Europe next year, so they're clearly ramping up production towards the end of this year.by cbg0
- Bluetti has a small battery pack for now. I think the options for consumers will balloon once CATL mass produce sodium ion cells. Solix/anker, jackery, ecoflow, etc all use CATL cells already.by syntaxing
- Na-Ion batteries are not practical for home storage right now. They have a much higher voltage range compared to LFP batteries, so regular inverters and chargers will not work reliably. Nothing insurmountable, but the supply chain is just not here.
Na-Ion cells are great for grid-scale storage because they potentially can go down to something like $20 per kWh. But bulk LFP cells are already at ~$60 per kWh, so their cost is not really a deciding factor anymore.
by cyberax - > Peak Energy is buying its commercial cells via contracts with Chinese suppliers
So really just assembly and sales then. I suppose it's a good start and maybe if business takes off they can figure out their own cells.
by tootie - Chinese companies started similarly 25-30 years ago.by nine_k
- Yeah, I had questions when Kurt Kelty was saying that Peak's battery was "kicking butt" after the article said Peak is still building their battery factory and currently buys its cells from China.
Is GM testing Peak's cells or some Chinese company's cells?
by Brybry - Surely this will just be Chinese hardware with a "made in America" label slapped on it. I can't fathom why anyone would allow GM of all companies to get any contracts
- I thought they were too busy with a hardon for hydrogen power for the future. When'd GM suddenly decide they wanted to get into the salt battery game too?
It's all a game of desperation for a failing automaker once again desperate for bailouts in new, fun ways.
First they run over a few kids with Cruise, then they decide they wanna get into the H-bomb game, now it's... molden salt?
by kotaKat - They have the manufacturing capacity others lack, and that’s hardly surprising when they have more STEM grads than previous superpowers have grads. Dedollarisation will severely limit debt-financed development for the US, so, if the US wants to regain its manufacturing might, they need to hurry up. That China will be a dominant superpower is a given, but it’s always healthy to have a multipolar world.by rbanffy
- This is the same story everywhere. Nobody has the know-how or the deep ecosystems needed to do these things.
India has a "made in India" mandate which is hilarious. >80% of solar panel (polysilicon, ingots, and silicon wafers) is from China. Situation is worse with batteries and EVs. Tata, which has been making vehicles for quite some time doesn't have any clue how to make EVs and is building an entire plant with a Chinese company (Chery).
Of course, everything will be labeled "made in ....".
In any country, the super rich have a simple algorithm:
1) Get it manufactured in China, slap your label and sell. Free trade is good for you, thousands of economists reports, blah, blah.
2) When its impossible to compete: China is security threat, we can't allow them. But we'll import most of it (80 - 90% of components) and still put our label.
Its easy to manipulate Govts, lobby or buy (Musk).