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by nippoo 143 days ago
By the same ticket, you really also don't want elemental sodium in your ear. Don't let the fact it's commonly found in sodium chloride alongside chlorine (something else you don't want in your pocket!) lull you into a false sense of security.

Sodium is actually more reactive than lithium and explodes on contact with water. There's a few things that make the battery chemistry less likely to undergo thermal runaway, but sodium is not a safe metal...

3 comments

How does the safety of sodium ion batteries compare to LiFePO4? It's not the presence of lithium that causes the problem, it's the way it's used in traditional lithium-ion cells. I've never heard of a fire being caused by LiFePO4 cells.
>Sodium is actually more reactive than lithium and explodes on contact with water.

TIL

Cursory LLM powered search suggests that this is true but not a particularly relevant metric for battery safety because battery failure modes aren't "throw elemental raw material into water".

I'm no expert and LLM research is well...yeah...but overall that still sounds like I should be trusting sodium more to my layman ears.

> Sodium is actually more reactive than lithium and explodes on contact with water.

Isn't the idea that it quickly dissociates water, and the hydrogen and oxygen bubble up ("explosively"?) and are easily ignited ?

So quickly that the dissociation causes the ignition, this is colloquially called an "explosion" : https://www.youtube.com/watch?v=5UsRiPOFLjk