Carbon-free storage for Electric Vehicles and Other Applications

A supercapacitor has been developed that uses no conductive carbon, potentially producing more power than comparable products.

Melanie GonickTo demonstrate the supercapacitor's ability to store power, the researchers modified an off-the-shelf hand-crank flashlight (the red parts at each side) by cutting it in half and installing a small supercapacitor in the center, in a conventional button battery case, seen at top. When the crank is turned to provide power to the flashlight, the light continues to glow long after the cranking stops, thanks to the stored energy.

Supercapacitors can be used in applications requiring rapid charge and discharge rather than longer-term compact energy storage, such as regenerative braking or power delivery in bursts.

Supercapacitors are energy storage devices that can be charged rapidly, but up until now have used carbon components, which require high temperatures and harsh chemicals in production.

The technology was a result of research by MIT scientists into metal-organic frameworks (MOFs), which are extremely porous, sponge-like structures. Although not generally very conductive they have a much larger surface area than carbon materials, an essential characteristic of supercapacitors. However, the material conducts ions (atoms or molecules that carry a net electric charge) very well.

The MIT researchers report that supercapacitors could play an important role in making renewable energy sources practical for widespread deployment including in electric vehicles.

The new devices, already match or exceed the performance of existing carbon-based versions, such as their ability to withstand large numbers of charge/discharge cycles. Tests showed they lost less than 10% of their performance after 10,000 cycles, which is comparable to existing commercial supercapacitors said MIT.