Apple working on new, more energy-dense batteries9
The new technology involves the implementation of the so-called "multi-step constant-current constant-voltage (CC-CV) charging technique," which will increase the energy density of the new battery cell. More efficient batteries will also allow making them smaller, resulting in a better use of space within the electronic device.
It is still unknown which one of Apple's upcoming devices will introduce the new technology to the market, if any ever will anytime soon. Lets just hope that the new batteries will be immune to self-combustion.
source: AppleInsider via Boy Genius Report