This looks interesting

Apparently a company named Sion Power has developed a Lithium Sulfur battery, that they are claiming has four times the battery life of the Lithium Ion batteries that most of us use in our batteries and laptops these days. Sadly, it can only manage about 300 recharge cycles at the moment, so it is not quite ready for prime time. Shame. Perhaps we will get portable fuel cells first, but clearly the dreadful battery bottleneck is somewhere where we will actually see considerable improvement within a few years.