The hybrid supercapacitor is reportedly six times as energy-dense as a commercially available supercapacitor and packs nearly as much energy per unit volume as a lead-acid battery.

Batteries can store a lot of energy in a small and light package, but they can't charge or discharge very quickly or last a long time the way supercapacitors can. A single device that combines all of these positive attributes could change the entire technological landscape of today, leading to lighter, compact phones and electric cars that charge in seconds instead of hours.

Professor Richard Kaner and Dr. Maher El-Kady have made an important step in this direction by creating a high-performance hybrid supercapacitor. Like other supercapacitors, their device charges and discharges very quickly and lasts more than 10,000 recharge cycles. But, according the scientists, their invention also stores six times more energy than a conventional supercapacitor, holding more than twice as much charge as a typical thin-film lithium battery in one fifth the thickness of a sheet of paper.