Short story is that you want to be in the upper left corner of this graph to power a motor vehicle. Supercapacitors are not yet as good as lead acid or lithium ion batteries. Fuel cells are in the right spot but far too expensive using platinum or palladium as catalysts.
Fight the Free Sh☭t Nation 
Should be that you want to be in the upper right of this diagram. Mis-typed.
So I take it you are not enthused about the work being done with Graphene which I believe puts it in the category of an Ultra Capacitor? I see some Graphene websites with PHD types experimenting with Silica and Tungsten DiSulfide in combination with the Graphene...