If you asked 10 of you readers what you think is the biggest problem that hinders the large-scale spread of electric cars, you would probably blame the oil lobbies in 3 (to think badly it is a pity but not a mistake frequently) and in 7 you would blame conventional batteries, too long to charge. Well, you are all right.
However, graphene supercapacitors are a more than concrete promise to solve the problem: they are able to charge an electric battery in just 16 seconds.
Santhakumar Kannappan of the Gwangju Institute of Science and Technology in Korea and his research group have built a device that despite its 'energy capacity' (they can store a little less energy than a normal lithium-ion battery) are able to charge and discharge batteries very quickly, and for several thousand cycles.
The technology tested consists in making graphene "sponges" by immersing the powder of this material in water and bombarding it with ultrasound. The treated powder is then "cooked" for 5 hours in round containers at 140 ° and at a pressure of 300kg per centimeter.
What do you get with this nice recipe? Impressive results: 150 Farrad per gram of capacity, capable of conserving energy at the density of 64 Watt / hour per kilo. A little less than a lithium battery, but capable of charging over time to count to 10 (slowly).
Not only that: dop or 10.000 loading cycles, graphene retains 98% of its capacity: it guarantees impressive stability and promises well for the electric cars of the future.
For more info here is a note from another University complex, the American one from Cornell: http://arxiv.org/abs/1311.1548
