China Could Dominate Sodium Batteries, the Next Big Advance in Power

Key quotes:

> Now China is positioning itself to command the next big innovation in rechargeable batteries: replacing lithium with sodium, a far cheaper and more abundant material.

> And sodium batteries come with a big advantage: They keep almost all of their charge when temperatures fall far below freezing, something lithium batteries typically do not do.

> Chinese battery executives said in interviews that they have figured out in the past year how to make sodium battery cells so similar to lithium ones that they can be made with the same equipment. Chinese giant CATL, the world’s largest manufacturer of electric car batteries, says it has discovered a way to use sodium cells and lithium cells in a single electric car’s battery pack, combining the low cost and weather resistance of sodium cells with the extended range of lithium cells. The company says it is now prepared to mass produce these mixed battery packs.

> The most immediately promising use for sodium batteries is for electric grids, the networks of wires and towers that transmit electricity... Sodium batteries need to be bigger than lithium ones to hold the same electrical charge. That is a problem for cars, which have limited space, but not for electricity grid storage.

> Unlike lithium batteries, the latest sodium batteries do not require scarce materials like cobalt, a mineral mined mainly in Africa under conditions that have alarmed human rights groups. The newest sodium batteries also do not require nickel, which comes mainly from mines in Indonesia, Russia and the Philippines.

Another way to produce sodium is by electrolysis of sea salt brine. You need lots of power. A by-product is hydrogen chloride which is a bit dangerous to handle. Pure sodium itself is also tricky: it reacts violently with water. Even humidity in air is enough to start a fire with pure sodium. There's a company in France that uses electrolysis to produce metal sodium: Metaux Speciaux SA.