Researchers at the Queensland University of Technology have added another hybrid supercapacitor design to the mix, promising the near-instant charge and discharge of a supercap with vastly improved energy storage on par with NiMH batteries.

The key concepts to understand here are energy density (Wh/kg), referring to the total amount of energy a device can store per weight, and power density (W/kg), referring to how quickly the device can move power in and out while charging and discharging.

Lithium batteries store energy in a chemical form, and are widely used because they offer a relatively high energy density, but as anyone who owns a smartphone or electric car knows, they charge fairly slowly. Supercapacitors, on the other hand, store energy statically rather than in a chemical form, meaning they can charge and discharge much, much faster without degrading their internal structures.