Fun fact, sodium metal has also been used to directly make wire. It has some compelling properties.

https://hardware.slashdot.org/story/19/06/08/1827250/the-los...

Lithium iron phosphate batteries are also safer than lithium ion batteries, and are already in wide production and use.

It’s great if we have more battery chemistries. It would also be great if people would recognize that thermal runaway in lithium batteries is already a solved problem. This would enable updating fire and building regulations, and allow installation of more batteries.

Is fire a solved problem? I thought it was minimised by lifepo4, but fundamentally if the bms fails you can still get a decent fire?

Interesting. It will also cause geopolitical changes because lithium is a rare earth mineral. And Sodium is obviously abundant.

This sounds still very academic though and be aware that these things take time to industrialise. Also sometimes it doesn't pan out in the end.

The fire hazard might be reduced but of course any battery storing so much energy in a small place has some kind of hazard. Hopefully the runaway fire providing its own oxygen is solved here though, this is the main reason it's so hard to put the lithium battery fires out.

Lithium is not a rare earth mineral. Huge pet peeve. This is a technical term. It’s also not particularly rare.

Rate earth minerals aren't necessarily rare, it means that you have to move a huge amount of earth to get a tiny bit of ore. That's still true for lithium and its mining pretty polluting too. And it's limited to specific regions globally.

Our sea is full of sodium however.

“Rare” as in “rarified”, not “uncommon”.

Even if the number of days is 10,000+, that's still a number /s

Feels like the article is overstating the risks of Li-ion. Modern Li-ion battery packs from reputable manufacturers are remarkably safe. An EV with Li-ion is still an order of magnitude safer than an ICE car. Yeah it can take a while for the thermal runaway to dissipate completely.. but it’s not a huge issue. You just have to keep it cool so it doesn’t set fire to other flammable materials (there are inflatable pools firefighter can use to surround the car with water)

Badly made Li-ion packs are a huge risk. But that’s a QA/Certification problem as with anything else (badly made charging bricks are also a risk.. don’t buy them on Temu). There have been CT scans published now showing how big a difference there is in the manufacturing of good and bad cells.

My knowledge may be out-of-date, but sodium-ion battery has a 30-50% lower energy density to lithium (200 Wh/kg vs 300-400). My understanding is it will be confined to cheaper solutions.

Wouldn’t mind not having lithium in my pocket. And in ears for that matter (earbuds)

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...

>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

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.

Look at where is Li and where is Na on that list. BTW a pure Natrium is also a very aggressive thing.

This could potentially open doors for short-haul e-aviation. Very interesting

In addition to the article’s stated benefits of faster charging than Li-ion, less temperature sensitivity, and lower propensity of thermal runaway, does switching to sodium also potentially address a raw materials problem? (Imagine if desalination could be made ecologically viable by harvesting the waste sodium for batteries…)

And what’s the downside? More complex chemistry to make the cathode?

They're also heavier, which is a concern for use cases like cars.

There's a good video I just watched that addresses the sodium battery industry and differences with current batteries: https://youtu.be/nrTCgZmUFCY

The downside is incompatibility with the existing tech (voltage mostly).

> harvesting the waste sodium for batteries

But what would you do with all the waste chlorine?

Sodium ion should be 40% the cost of lithium ion. 60% for LFP.

But scaling is still underway.

The keys to recognize for advanced sodium ion state of the art is that you should be able to do a 300 mile car now with sodium ion that fundamentally is cheaper than ice drivetrains.

However, I still think hybrids are the next 20-year solution