A supercapacitor is essentially device that can be quickly charged up, can hold its charge for a long time, until it needs to release it. Similar to a battery? Well, in function kind-of, in terms of how they work, a mile off! Capacitors use static electricity as opposed to chemistry to store energy: two conducting metal plates, with a insulator in between. This allows a build up of charge on one side of the metal plates, and then when the time is right, through control of the insulator, you can release this build up of charge.
But what makes a supercapacitor, well, super? Let’s use the analogy of water. In a regular capacitor, the metal plates are just your average kitchen cloth. When in a super capacitor, they are much more porous, large sponges. This is the field which researchers are working at the most, finding new materials to use for the plates in the supercapacitor. Recently, some Korean scientists have found a way of using a form of graphene to be able to store a far larger amount of energy than what has been previously achieved. Supercapacitors are also much more able to recharge quickly, very useful when capturing large amounts of energy under braking in a matter of seconds. However, the main drawback with supercapacitors at the moment is their low energy density compared to traditional batteries. So think of it as a dilemma like this, would you rather have a phone that you can charge in a minute but only lasts half a day, or one that takes 4 hours to charge but lasts a day and a half?