Lithium-ion batteries have transformed our lives. They make our smartphones possible. They power our laptops and most other rechargeable devices—including, increasingly, our vehicles.

We’re even hoping to put giant batteries on the grid, to store solar- and wind-generated electricity when it’s being produced to use later when it’s not.

With that increased demand, lithium has become expensive. Its supply is volatile and controlled by just a few countries.

So, battery scientists are looking for an alternative. And they may have found it—in sodium. It’s a light metal related to lithium and is globally abundant and cheap, just 2% the cost of lithium.

And it can be used in similar ways—with advantages and disadvantages.

Sodium-ion batteries maintain most of their performance in cold temperatures, where lithium suffers.

They’re less prone to runaway thermal reactions, meaning fewer fires. And may be easier to recycle.

However, their energy density is lower than lithium and their lifespan is shorter, while their size and weight are greater.

This may make sodium batteries best suited for the grid. But scientists are working to improve them and hybridize sodium with lithium to leverage the strengths of both.

Combined designs could be smaller, longer lasting, safer, hardier and cheaper. Only time will tell if they could scale up enough to transform our electrical systems … again.