It promises significantly longer cycle life than traditional lithium-ion batteries, as well as the ability to operate in extremely hot and cold climes.

On the outside, the affectionately named DE-C55L-9000 looks similar to the vast majority of power banks on the market, with a rounded brick shape housing its 9,000-mAh battery, a 45-W USB Type-C and an 18-W Type-A port, and charging indicator LEDs.

What's more interesting than the rest is the tech inside. A sodium-ion battery is pretty similar to a lithium-ion battery in terms of how it works and how it's constructed – but it uses cheaper and more abundantly available sodium for the cathode material, and sodium salts instead of lithium salts for the electrolyte.