Technology Review had a chat with MIT material scientist and battery expert Yet-Ming Chiang about future bateries. He claims in the next ten years we'll have batteries with double the capacities of today's batteries, without sacrificing safety.
TR: So how can batteries be improved?
YC: There really are two routes to as-high or higher energy systems that are safer and lower cost. One is better control of manufacturing quality. Based on what I've read in the press about these two recalls [Dell and Apple], it was a manufacturing problem that resulted in metal particles that created some internal short [circuit] problems. So that is quite simply a manufacturing issue.
The alternative approach is to try to make the chemistries intrinsically safe, or at least safer. People are working on this in many laboratories around the world..