BYD / Denza z9 gt claim 10-70% in 5 mins, 97% in 9 mins. With a range of ~1000km this seems to crush these results? I don't know enough about this space to know if I am missing something here, but would love to know because something about this feels more exciting than i think i am grasping. anyone know?
MisterTea•56m ago
I see no charge rate numbers so there is no way to compare. however, these sodium batteries are cheaper, do not require lithium, and are operable at lower temperatures of -20C/-4F. Sounds like a bit of a win and opens the door for battery options in cars.
_aavaa_•48m ago
And the fire safety risks are significantly reduced (thermal runaway is much harder). They can also be transported and stored completely discharged, something not done with lithium ion batteries because of it degrades them much more than regular usage.
adrian_b•28m ago
The sodium-ion batteries are said to work satisfactorily down to -40 Celsius = -40 Fahrenheit.
-20 Celsius just happens to be a temperature for which a retention ratio was specified in the parent article, and not the limit of the operation range.
cbg0•46m ago
The range claims depend on the size of the battery pack. The Denza has a larger pack than what is quoted in the article. Also, the Chinese CLTC range ratings are overly optimistic with 1000km CLTC being ~820km WLTP or ~700km EPA.
IneffablePigeon•46m ago
This article is about a sodium-ion battery which is a different chemistry to the one BYD claimed those results on (that was LFP).
Sodium-ion is exciting because it has the potential to have less degradation over time, much less sensitivity to cold and less reliance on rare earth metals. Could also end up significantly cheaper. However it has struggled to reach the same energy densities and so hasn’t been practical thus far.
This seems like a big step towards it being a practical technology choice for certain models, if it bears out.
readthenotes1•45m ago
Another better battery bulletin
WarmWash•33m ago
I don't know what chemistry exactly these cells are using, but in sodium-ion batteries, prussian blue analogs as they are called are common anode materials. Overcharging these cells can lead to a release of hydrogen cyanide gas, notoriously known as Zyklon B.
It has damped my enthusiasm for perusing it as a potential future home energy storage solution.
cyberax•17m ago
Just wait until you find out about hydrogen sulfide from overcharged car batteries.
Also, I think HCN can be scrubbed by adding a special absorptive cap onto the battery.
cyberax•20m ago
Just remember, the US Na-Ion battery startup died last year with _products_ _in_ _warehouses_ just because it couldn't get a UL certification. All it needed was a bridge loan.
And the government did nothing.
btheunissen•8m ago
Starting to think that the American century of humiliation meme was prophetic.
iugtmkbdfil834•3m ago
One could argue that in that case, doing nothing was very much a choice.
Grimblewald•1h ago
MisterTea•56m ago
_aavaa_•48m ago
adrian_b•28m ago
-20 Celsius just happens to be a temperature for which a retention ratio was specified in the parent article, and not the limit of the operation range.
cbg0•46m ago
IneffablePigeon•46m ago
Sodium-ion is exciting because it has the potential to have less degradation over time, much less sensitivity to cold and less reliance on rare earth metals. Could also end up significantly cheaper. However it has struggled to reach the same energy densities and so hasn’t been practical thus far.
This seems like a big step towards it being a practical technology choice for certain models, if it bears out.