I was reading over the weekend about new battery technology. It was in the context of the mobile phone industry so I don't know if it could be adapted to motor racing. These new batteries were aluminium based rather than lithium ion and could be charged (on a mobile) in around a minute rather than a couple of hours. They are also lighter, more flexible and more stable.

Again in a mobile context, they would stand 7,500 recharges as opposed to the current 1,000 that lithium ion batteries will stand before they 'die'. The down side it that it only produces half the voltage of a current battery, but the boffins believe that they can improve this in the next few years.