Hacker News Reader

Hacker News

Comment by MaKey | Hacker News Reader

Full thread

MaKey

Key data:

- Cathode material: Prussian white

- up to 160Wh/kg (2nd generation targets 200Wh/kg)

- can charge in 15 minutes to 80% SOC at room temperature

- 90% capacity at -20°C

- Pricing estimates: 26-46$/kWh at GWh production scale, 77$/kWh at smaller production scale [0]

[0] https://twitter.com/DKurac/status/1402854199080099841

View on HN

LFP is reported at ~$80/kwh for large Chinese buyers. Are those figures accurate?

Sure its good to have alternatives, but seems LFP will takeover the world except for the premium uses (especially as we get chargers everywhere).

> LFP is reported at ~$80/kwh for large Chinese buyers. Are those figures accurate?

Yes, automotive buyers were having it for less than $100 per kWh for at least 5 years now. Still not sure for which density range these prices are. 190wh/kg LFP cells are now available in retail, and 200wh/kg been around for at least 2 years for automotive, and been used in EV busses from a few manufacturers.

It wouldn't be a stretch to say that biggest, and longest term contracts can get it to $60 per kWh.

Lowest end, storage class LFPs must also be quite cheap in lower volumes, and haven't looked at them for a long time.

Genuine question, as a private individual looking into residential storage, what kind $/kWh should I be expecting if I could get the system and install it myself, and why is it so much higher than the big manufacturers? Is it just volume?

The volume, and shipping hurdles are sure a part of thing, but there are persistent speculation about nearly every battery maker putting no resale clause on the contract, and enforcing them zealously to keep retail prices high, so their distributors can make a buck.

Depending on your size. Inverter prices vary most dramatically for minor features, and options.

For batteries only, with shipping, and duties, think of a double of alibaba.com price.

And yet Tesla Megapack volume priced at $280/kwh [1], for 2023 delivery!

Argh. Where is the big cost? AC convertion? the cooling? pack isolation and protection ? The special logo ?

[1] https://electrek.co/2021/07/26/tesla-reveals-megapack-prices...

With them getting half of inputs for their batteries from abroad, it's not a big stretch to say that their own cost is still above 100$ pew kWh

What’s LFP?

lithium ferrophosphate

Says Google

Sounds competitive with Lion and possibly cheaper? What’s the catch?

density still lower than li batteries at 300wh/kg will probably never overtake li ion batteries. But sodium is much more widely available than lithium, and it doesn't need cobalt.

300wh/kg is not where we will ever see any conventional lithium battery chemistry get.

Best mainstream cells cars are made with today are all around 200wh/kg.

240wh/kg NCM cells are there, more or less widely available, but they are almost the same stuff with higher rating, and lower cycle life. Manufacturers basically nudging digits.

If they reach same 200wh/kg, along with equal cycle life to LFP, it can be big.

If they can get them comparable in weight and power this could be neat for size size reasons. For the same weight but ~1/4th the size is interesting.

yeah, I think the big information is CATL is industrializing NA ion batteries and specifically calling out supply chain partners to do so. Its one thing to have a lab result, another thing to industrializing, forming upper stream supply chain and its own manufacturing capacity. The latter will need serious cash, time and human resource investments. CATL is a public traded company, margins, revenue is crucial. They also have pretty good lithium ion NCM and LFP batteries, and are researching solid state Li batteries so they know a thing about battery chemistries. They also in pretty serious competition with other battery makers and supplies big name car brands. So for them to throw their own cash at this new technology means they see long term advantages. I think time will tell what it will end up with.

The second anyone starts to order it in sizable quantities like for a utility installation or auto production run the prices spike and don’t recover until they hit competitive scale (best case) or some yet unknown scientific breakthrough (worst), all the while trying to catch up to LiIon.

The hard science part for the first generation seems to be done, what now follows is scaling up the production. CATL targets 2023 for mass production. As the same production processes for Lithium-ion batteries can be used this doesn't seem unrealistic.

This is a feature, not a bug. If CATL can make a huge margin, that will incentivize them to scale much more rapidly, which will be good for everyone.

Less energy density, can't find any information on power density, faster charge cycle degradation (i.e. maybe a third of the lifespan of lithium chemistries), lab results should always be treated with some skepticism.

The spider plot at the bottom of the page shows the "long life" axis being the same as LFP, which tend to have much better durability than most other lithium ion chemistries. So if that's not marketing fluff then degradation shouldn't be much of an issue.

Energy density does seem to be the main weakness that they're acknowledging.

> Sounds competitive with Lion and possibly cheaper? What’s the catch?

All previous works on sodium batteries showed very low cycle lives for both cathodes, and anodes.

Since they are not giving it out now, I guess that's it. And this may well be why they keep nailing solely on the point of it being operational at -20C° (which is a big thing for any lithium battery, still)

Another thing I will note is them specifically comparing this to an LFP battery.

CATL been very late to the LFP party, especially for the high-end automotive LFP cells.

Companies which made a bet on LFP early are now coming with 200+wh/kg cells, which is already bigger than commodity automotive NCA, something which Foxconn (CATL) makes most money on.

This is a kick below the waistline move to at least throw doubts about business expansion for LFP makers. Currently, 200wh/kg LFP cells are just only now hitting the market, and these LFP cell manufacturers are still making the lion share of their revenue, and profit on storage class, and low-end cells.

If LFP manufacturers believe the new chemistry can wipe out their current cash cow, they will think twice about putting money to expansion in automotive cells.

I thought lithium is a light element so the Lion batteries are lighter. But sodium might be useful for non automotive applications like the power grid batteries.

Isn’t lithium actually a small part of the battery?

Yeah it's like a few percent by weight. Most of the weight is the anode and cathode materials. That's tantalizing because in theory there is a lot of room for improvement.

Compare with lead acid batteries where most of the weight is the lead.

> - Cathode material: Prussian white

Ferrocyanides — not the cheapest compound to synthesize

That's what I'm interested in. And yes, it does seem that the use of the artist's pigment name seems intended to obscure the fact that this is a complicated material.

Any solid state chemists here who can enlighten us?

Ferrocyanide anion has a complicated looking structure but it is easy to synthesize.

The input materials are hydrogen cyanide (cheaply produced from methane and ammonia via the Andrussow process), calcium hydroxide, and iron(II) chloride. Combined, they form ferrocyanide.

Despite the toxic hydrogen cyanide used in production, ferrocyanides are nontoxic because the cyanide is so tightly bound to iron. Potassium ferrocyanide is used as an anticaking agent in table salt.

I have made Prussian blue before by roasting dried blood (organic fertilizer) with sodium hydroxide, extracting with water, and letting it partially oxidize in air. Blood provides both iron and nitrogen. This was an industrial process, historically, before artificial nitrogen fixation.

Indeed, I instantly recalled the same "blood and sodium hydroxide" stuff from high school chemistry class, and thought of it still being a thing.

It doesn't seem to be too expensive, nor too cheap: https://www.alibaba.com/products/sodium_ferrocyanide/CID8020...

So stationary?

Tesla already builds Model 3s with LFP batteries which the announced 2nd generation of CATL Sodium-Ion Batteries will be comparable to in terms of capacity. So not only stationary.

Presumably the LFP batteries will still have quite an advantage in terms of density.

Not huge, if these numbers hold up. On paper this for sure looks like a really competitive technology, especially for grid storage and solar backup kind of applications. But we'll see.

Reply on news.ycombinator.com