Samsung is always improving its hardware to suite curved and bendable devices. Samsung SDI revealed a small Curved Battery with a capacity of 210mAh, this curved batter will be used inside wearable devices to provide more battery life, faster charging and thinner design.

The newly released battery is manufactured using V-bending technology to increase its energy density. It sits in an aluminum foil package to which allows it to be flexed with no strain.
Samsung Gear 2 Smartwatch has a similar one inside of it. This battery is going to be included on Samsung’s future Smart wearable devices.
Source (Translated)