Thanks to advancements in technology, people can now do more and more with their gadgets. Mobile phones, for example, are no longer just for talking - they can be used to listen to music, take photos and soon even to watch movies. But this also means that new sources of power will be required to accommodate the technology - and at Carnegie Mellon University in Pittsburgh, Pennsylvania, a team of researchers led by Prof. Prashant Kumta has recently synthesised a new material that can store more energy than the supercapacitors used today.
Unlike a battery where energy is stored in a chemical form, a supercapacitor is an electrical device that stores energy in an electric field. This field is generated by negative and positive plates in the capacitor - and their "super" status comes from their ability to hold four times as much charge as a normal capacitor.
Currently, supercapacitors are made from ruthenium oxide but the high price of this compound limits their use in a wide range of technologies. They are most useful in applications like hybrid cars and robotics where a large, fast pulse of energy is required. Compared to a normal battery, a supercapacitor can also last much longer.
The new material - called nanocrystalline vanadium nitride - could be a viable alternative to ruthenium oxide. It has a capacitance that is almost two times greater and can also store energy for longer. The structure of the material has two layers: it has an outer shell of vanadium oxide and an inner core of vanadium nitride. This set-up enables energy storage because of electrochemical reactions that occur on the vanadium oxide surface - which generate an electric charge. The vanadium nitride interior stores the charge generated.