Comment by scythe | Hacker News Reader

Comment by scythe | Hacker News Reader

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>This is a little under 2x the density of [the best] current batteries.

[brackets mine]

But the best batteries contain unacceptably high levels of cobalt. Practical EV batteries are made with nickel or iron, maybe vanadium someday, and have lower density than pure LiCoO2.

>CATL is already producing a ton of batteries, lending them some credibility.

A couple of years ago CATL claimed that they had figured out how to make durable sodium-ion batteries with a ferricyanide cathode, to be released in 2023. The press cheered about the end of lithium dependence.

Yesterday, not long before this announcement, it was revealed that CATL's "sodium-ion" battery contains lithium:

https://cnevpost.com/2023/04/20/catl-byd-sodium-ion-batterie...

"CATL and BYD's sodium-ion batteries to be put into mass production will both be a mix of sodium-ion and lithium-ion batteries, according to local media."

[sad trombone noises]

While I agree that the blurb you quote strongly implies that the sodium-ion batteries contain lithium, I don't think the article itself really says that.

> CATL and BYD's sodium-ion batteries will both be carried in mass-produced vehicles within the year, and they [the vehicle battery packs] will both be a mix of sodium-ion and lithium-ion batteries, according to a report by local media 36kr today.

By my reading of that, and the rest of the article, it's saying that the vehicle battery will be assembled from of a mix of sodium-ion and lithium-ion battery cells, not that the sodium-ion cells contain lithium.

> With its pioneering AB battery system integration technology, CATL has achieved a mix of sodium ion and lithium ion, allowing them to complement each other and thus increase the energy density of the battery system, Huang said at the time.

Basically, a "battery system" using only sodium-ion cells does not yet have enough energy density to support their range targets, so they are using a mix of cell types to improve the energy density and increase the vehicle range.

My EV with cobalt in the batteries seemed practical to me.

And nothing wrong with having some lithium in their battery. The important thing is how much cheaper is it.

Your EV probably has the usual NMC or NCA chemistries which have around 10-20% cobalt. I don't know of any car that uses a 100% LiCoO2 cathode — it's just not practical.

Cobalt is practical if you want to make low millions of cars. It ceases to be practical if you want to make a billion cars. There just isn't enough of it readily available to scale.

What makes the Cobalt unacceptable?

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