Sony announced an improved lithium-ion battery. This battery offers a lifespan four times greater than current lithium-ion batteries, possessing a retention capacity of 80% after 2,000 charge-discharge cycles (link).
Without getting too technical about the whole thing, the new battery uses as its cathode material olivine-type lithium iron phosphate, which Sony says is ideal for the job "due to its robust crystal structure and stable performance, even at high temperatures."
The material also apparently contributes to the battery's faster charging time--it can hit 99 percent of its full capacity in 30 minutes (approximately half the charge time of Sony's current lithium ion battery line, which mainly use cobalt oxide-based cathodes).
For the moment, the batteries will just be showing up in motor-driven devices like power tools--so if you own a cordless band saw, you're in luck. Those of us who just need to worry about powering our iPods and laptops, however, will have to wait a little while.