this post was submitted on 09 Aug 2026
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New sodium-ion battery skips mechanical cooling with 97.9% efficiency (interestingengineering.com)
submitted 2 weeks ago by Return_of_Chippy@lemmy.world to c/technology@lemmy.world
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I've been hearing about these for a few years now. Huge if they work out at a large scale.

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[–] Natanael@infosec.pub 9 points 2 weeks ago* (last edited 2 weeks ago) (3 children)

1 C is defined relative to 1 hour for full discharge and 3 C means a 3x faster discharge rate (full capacity can safely be discharged in 1/3 hour, or you can discharge 3 cells sequentially in an hour). Good lithium cells tend to be above 5C, can reach 10C for peak load or if cooled.

For a large enough battery it doesn't really matter, but for dense portable ones a lower C rating means you have to discharge from more cells simultaneously to maintain a given output. That makes it more complicated, and you have less headroom to the battery's maximum Watt output if you need to accelerate a car hard suddenly.

[–] Pelicanen@fedia.io 2 points 2 weeks ago (1 children)

NMC cells typically operate around 1-2C and LFP cells 1-3C. If you want to achieve 10C then you're probably gonna have to look at LTO cells. All of these are lithium-ion chemistries but they each have different characteristics.

[–] Natanael@infosec.pub 1 points 2 weeks ago

(for context most my knowledge of these cells are from single cell +5000 lumen flashlights :)

[–] captainlezbian@lemmy.world 2 points 1 week ago

And here I was confused why coulombs were being used as a charging rate…

We need to abandon the "use a letter for this unit/property" crap and accept that the alchemists and accountants had it right.

[–] ryannathans@aussie.zone 1 points 2 weeks ago (1 children)

The comment I am responding to is about charge rate, not discharge rate

[–] Natanael@infosec.pub 2 points 2 weeks ago (1 children)

For most batteries that's the exact same rate

[–] ryannathans@aussie.zone 11 points 2 weeks ago* (last edited 2 weeks ago)

Sodium ion batteries are asymmetrical, pushing charge current hard can drive the anode negative enough to deposit metallic sodium causing formation of dendrites which destroys the battery