Why so many battery companies are suddenly betting on sodium over lithium

Sodium‑ion batteries were recently named one of MIT Technology Review’s top ten breakout technologies of 2026 – and for good reason. Behind the headlines sits a simple question: why are so many researchers and companies suddenly betting on sodium over lithium? In this article, Ronnie Mogensen, co-founder of Altris, explains how his curiosity led to Prussian White, and why sodium‑ion offers a more accessible, robust and sustainable way to electrify everything from cars to the power grid.

From Uppsala lab experiments to Prussian White

Altris’ sodium-ion battery technology grew out of a fascination with electrochemistry in a laboratory at Uppsala University. At first, we were exploring sodium for solid‑state electrolytes rather than thinking about battery cathodes at all, intrigued by its “Dr Jekyll and Mr Hyde” personality – an element that is found everywhere, yet is highly reactive. That curiosity turned into frustration when we realised how few good cathode materials existed, so we started to synthesise our own and arrived at Prussian White, a crystal structure of iron, carbon, nitrogen and sodium. When it outperformed everything else in the lab, it stopped being just another experiment and became the starting point for Altris.

How sodium-ion differs from lithium-ion

At Altris, we often get questions on how sodium-ion differs from lithium technology. Essentially, they are based on the same basic principle of ions traveling between the anode and cathode, but what’s different about sodium is that it opens a wider range of elements that you can use for those electrodes. Instead of relying on rare minerals like cobalt and nickel, sodium-ion batteries allow you to use abundant minerals. This shift towards widely available, low-criticality elements enables more robust supply chains, lower environmental impact, and greater geopolitical independence in battery production.

Prussian White: a robust all-round cathode

If you study electrochemistry, you soon learn there is no such thing as the perfect battery material. Most chemistries have an Achilles’ heel – a weak point you have to work around. What’s so interesting about Altris’ Prussian White is that we haven’t seen any obvious weaknesses of that kind. Instead, it behaves as a very well‑balanced cathode: strong on safety, cycle life, power and temperature performance without one property standing out as the clear trade‑off. This makes Prussian White great for a wide range of uses, such as low-voltage automotive applications and energy storage.

This balance becomes clear when you look beyond energy density, which stil ldominates most battery discussions. In areas like power density – the ability to deliver bursts of energy fast (think starting a car at minus 40) – Prussian White consistently outperforms lithium-based cathodes. It also holds up better when fully charged, left to sit for long periods, or discharged completely without significant degradation.

The future for sodium-ion

So, what does the next decade hold for sodium-ion batteries? At Altris, we believe that sodium-ion is today where lithium was 30 years ago, which means the biggest leaps in performance and new applications are still ahead of us. In that light, building only lithium‑ion gigafactories risks locking the industry into yesterday’s options at a moment when electrification needs to speed up, not slow down. Our ambition is not to replace lithium everywhere, but to match the right chemistry to the right application and in the process rethink how, and where, batteries are made.

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