The limitation in physical flexibility of portable devices can be defeated thanks to a super-thin and flexible battery invented by Korean scientists. The battery which seems to be commercially viable, can lead to gadgets that can be folded away into your pocket. The battery remains one of the largest single parts of any portable device but this lithium-ion battery is razor-thin and retains its voltage even while being bent. A folding battery would be a big step toward bendable gadgets.
Read more here - http://mashable.com/2012/08/06/flexible-battery/