Photo: Wikipedia, CC
But With all the Advantages of Supercapacitors
As you can see above, graphene is a one-atom thick sheet of carbon atoms, very similar to carbon nanotubes, except for the "tube" part. This wonder-material has very interesting electrical properties that have allowed researchers to create a graphene-based supercapacitor that exhibits a "specific energy density of 85.6 Wh/kg at room temperature and 136 Wh/kg at 80 °C." This is similar to nickel-metal hydride batteries, the chemistry used in most current hybrid vehicles (like the Toyota Prius and Ford Fusion hybrid).The main difference is that supercapacitors can be cycled an almost unlimited number of times (they don't lose their ability to hold a charge like batteries), and they can be charged and discharged extremely quickly (as long as you have a "fat pipe" to supply the power). This would make them ideal for hybrids and electric cars if their power-density was high enough (so far it isn't) and their cost went down.
This breakthrough is bringing closer the day when the power-density part of the equation is solved, and while the cost of graphene is still high, it should go down with volume production (after all, it's only carbon).
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