Sustainable sodium

Advanced materials scientist Maria Forsyth is trying to build the battery of the future.

- Maria Forsyth

When I was doing my PhD, there was no such thing as a lithium-ion battery. The first was commercialised in 1992, and for the next two decades or so, it was all about lithium.

My work was always parallel to that. For the last 30 years I've been investigating how we can improve the chemistry of all sorts of batteries, capacitors, fuel cells and solar cells. These are hugely important for the transition to clean energy, but we've got to be careful that they don't create new problems. It's important to make these devices safer, to make them last longer and to get more energy out of them.

The technologies we're creating must also be sustainable, and designed for recycling in a circular economy.

For example, in Australia we're blessed with a lot of spodumene - a mineral from which we extract lithium. But the majority of lithium comes from the salt lakes of South America, where mining has an environmental impact.

So for me, the "next big thing" is sodium. It's in seawater; it's everywhere. Sodium batteries aren't going to replace lithium, but because of the demand for more and more energy, we're going to need to look at multiple technologies.

Most types of modern batteries work on the same principles. It’s the materials that are different. Then it comes down to how much voltage you can get out of the battery, how much it weighs and its capacity – how much energy you get per kilogram, or per volume.