The return of the sodium battery

It’s an old concept, the sodium battery: it has advantages in terms of power, charging speed, price, and pollution.

It’s an old concept – Jules Vernes saw it as the future – very quickly crushed by its historic competitor, the lithium battery, today in all electric cars, more energy dense. Yes, but the sodium battery has great advantages in terms of power, charging speed, price and pollution. Details from Hervé Poirier, editor-in-chief of the magazine Epsiloon.

franceinfo: Explain to us this comeback of an old idea: the sodium battery…

Hervé Poirier: It was the energy of the Nautilus: “Sodium batteries should be considered the most energetic”, explained his commander, in 20,000 Leagues Under the Sea, by Jules Verne. And sodium is found in salt! “The sea itself provides it to us”, praised Captain Nemo. En fact, we stayed in a world of lead batteries for a long time…

It was only in the 1980s that the idea of ​​sodium returned to power future electric cars. Except that it was one of its cousins, a lighter atom with equivalent chemical properties, which quickly won the day: lithium.

For a simple reason: it stores twice as much energy per mass or volume. It has become the battery for all electric cars (and phones, and laptops). And today it’s a rush. Gigafactories are popping up all over the world. The European Union will need 18 times more lithium by 2030.

And yet sodium is coming back into the race?

In the earth’s crust, there are 1000 times more of it than lithium, not counting that present in the sea. It is better distributed, less expensive, less polluting. The battery, of course, is less energy dense, but it has more power, recharges faster, ages more slowly, with less risk of runaway and explosion. And it is quite easy to reconvert the production tools developed for lithium. Result: at a time of the global rush for lithium, the old idea is coming back into favor.

For several weeks, Tiamat, born from work carried out at the CEA and the CNRS, has been offering, in partnership with a DIY store, a first consumer product equipped with this technology: a cordless screwdriver. And announces that next year it will build a “megafactory” near Amiens (not yet a “giga”). Other start-ups are on the bridge. As well as the Chinese giant CATL, world leader in batteries.

For what applications?

For cars, this will probably concern niche markets, such as very short-term rentals, or in addition to lithium batteries. A sodium electric car prototype, with a recharge time of 5 to 10 minutes, was nevertheless presented this year in China. But the potential is vast.

The main market could be large storage batteries, near wind or solar farms. The submarine trail, no offense to Captain Nemo, has not yet been considered…