Half a century ago, the future of batteries was sodium. With it being an element that ionizes easily – giving up one of its electrons – the ions go back and forth between two oppositely charged plates, generating a current.

But then Sony commercialised the first lithium battery in 1991 and the battery industry hasn’t looked at sodium since.

Now, however with numerous problems with lithium batteries such as raw material supply and costs, researchers and companies are taking a second look at sodium, according to an article in Wired.

This summer China’s CATL, one of the world’s largest battery makers, announced during its first online event that sodium would play a role in the electrified future and starting in 2023, it will begin placing sodium cells alongside lithium ones inside the battery packs that power electric cars.

Dr Robin Zeng, chairman of CATL, unveiled the company’s first-generation sodium-ion battery, together with its AB battery pack solution – which is able to integrate sodium-ion cells and lithium-ion cells into one pack – at the event. CATL said that sodium-ion batteries will provide a new solution for the use of clean energy and transportation electrification, thus promoting the early realisation of the goal of carbon neutrality.

However, Shirley Meng, a battery scientist at the University of California, San Diego, sees the strengths in sodium-based batteries not in areas requiring smaller sized batteries which is where lithium shines, but for the batteries that will manage the load within microgrids and keep lights on at night when the rooftop solar panels are in the dark.

Meng told Wired that technologies like sodium – and other lithium alternatives, which include zinc and vanadium – are also an opportunity for places like the US, which lacks an extensive battery industry, to build one. Meng and other UC San Diego researchers recently launched an initiative to set up manufacturing techniques for solid-state sodium batteries, a next generation of technology that would be far safer and more energy-dense than the batteries available now.