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.
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.
What does round trip efficiency mean here?
How much energy you get out of a full charge, divided by how much energy you need to fully charge it. It’s around the 90% mark for lithium based tech, no idea what it is for these sodium ones
The numbers I’ve seen: LFP: mid 90s Sodium: low to mid 80s
LFP seems better for cars unless you live in an area that deals with extreme cold. Sodium is better (cheaper) for fixed, large quantity storage where energy density is not as critical and lower efficiency is an acceptable trade off for lower price.