Imagine charging your cell phone in just a few seconds. Or consider how transportation would be transformed if it took only a few minutes to fuel up an electric car.
The technology for rapid-fire power-ups has been around for decades—in supercapacitors. Supercapacitors not only charge faster than batteries, they last longer because they don't suffer the physical toll in charging and discharging that wears down batteries. They also have a number of safety advantages. However, supercapacitors' super size—they have to be much larger to hold the same energy as batteries—and their super-high cost have held them back.