At Northwestern University, engineers have made a new type of graphene* electrode: one punched with many microscopic holes. It could store 10x as much power (30,000mah instead of 3000) and charge 10x faster. As with any new technology, a big problem is to make it cheap enough for consumers to buy.
* Graphene is a single layer of carbon atoms, usually on a substrate. "Graphite" is actually many layers of graphene.
Stanford Extreme Tech. 2011.