NEC has been dabbling in ultra-thin flexible batteries for a while now, but the latest version of its ORB, or organic radical battery, measures in at a mere 0.3mm thick. Making it thin enough to be used even in a credit card.
The ORB technology results in batteries that outperform even lithium-ions, and since they can be created using a special printing process, they can easily be integrated into circuit boards during the manufacturing process.
NEC envisions the latest generation of these batteries being used in electronics like flat screen displays, flexible ereaders that feel more like paper, or enhanced debit and credit cards. Imagine how convenient a Visa with a built-in display showing your current balance would be. Or if it had greater wireless capabilities so you wouldn't even have to take it out of your wallet to make a purchase. Wait, maybe that's not such a great idea after all. [NEC via Japan Tech Niche via The Verge]