cross-posted from: https://lemmy.zip/post/48958993
energy density of 175 Wh/kg
CATL explained that sodium-ion batteries have slightly lower energy density than lithium-ion batteries but provide distinct advantages in low-temperature performance, carbon footprint, and safety.
These things are a game changer. For a car, you don’t need the energy density of li-ion. They don’t fly, they don’t get carried around by people.
They are significantly safer than lithium-ion. They don’t burst into flames if the container is breached. They don’t build up hydrogen bubbles. I believe they have a higher cycle lifespan. And they don’t degrade when fully charged or discharged like lithium do.
They are also much more environmentally friendly to develop and cheaper to produce (which mean they will never be allowed into the US because of Elon Musk).
I really hate how all these headlines give battery capacity as a distance, as though that was a meaningful measure or allowed comparing different technologies.
But it’s all stupid people and marketing people understand more=better cheaper=better. I think it’s why ev adoption has been so poor, questions I get asked are what’s the range like? Doesn’t it take forever to charge? And aren’t they really expensive?
They do the same thing with grid storage batteries and I hate it. “Our battery lasts 20 hours!” Think it was a better unit like watts per 4 hours but media and marketing mess with it.
They are cheaper and the low temperature performance is better than LFP, but the round trip efficiency is less than LFP.
They also have better thermal stability, so less risk of uncontrolled fires.
AFAIK, LFP thermal runaway can’t start fires. NMC or other lithium chemistries can and they scare me, but LFPs are pretty damn safe. That being said, I’m still stoked for sodium chemistries to be developed. If the round trip efficiency issues can be solved, then I think it’ll be a great solution for residential power storage.
Question is… How much cheaper…
LFP is almost at the price point we could all have a freezer sized battery pack in our house, drastically changing the grid, and allowing a place for all that wind/solar to store energy.
If Sodium is a fair chunk cheaper, then it will totally be worth buying a house battery pack. Buying energy on the cheap at certain times of day, and using the battery when energy prices are high.
Potentially 1/10th the price according to this video I stumbled on about it a couple of days ago!
As long as the efficiency is outweighed by price, it could move us in the right direction. Hopefully we can pick up the efficiency in time. These would also be good for my future load-shifting (charge during off peak, low carbon electricity) and maybe solar system at home.
“slightly lower” == 2/3rds, apparently. the model 3’s pack is 250Wh/kg. also, 500km range in what? the only way you could fit an equal-range battery in a contemporary compact vehicle like the model 3 would be if it had almost double the density of Li-ion.
The model 3 is not a compact vehicle…it’s a regular size sedan.
it is apparently D-segment, yeah. i have a C-seg car and have found the model 3 to be very similar in size, but maybe that’s just a matter of the height making it look smaller.
