Actually the problem is not battery life but heat management. If you have hardware with mobile phone form factor and consume energy so much that you drain your battery empty in a couple of hours, you start to have bad problems with heat. This means that you actually have to think power consumption issues when designing new processors for mobile gadgets and better power sources are not the solution for power consumption issues. Sure, with a bigger battery you can have your device run longer but you still need to limit the power consumption because of the heat.
Note that there are many-many components that use quite a bit of that energy - the screen, vibra, speakers, CPU, memory, camera, flash, GSM/WiFi/BT radios, GPS, etc, etc. If you fitted a modern superphone with a super-energy-conserving CPU, the device would still use considerable amounts of juice.
The other is - the CPUs are mostly generating heat because their internals are not superconductors. HOWEVER, the technology they are made in very much influences this waste-heat effect, that's why a 32nm process is a LOT better than a 180nm process - even if you had literally the same transistor layout in there, the smaller components mean less resistance -> less heat. Manufacturing technology will also allow you to use lower voltages, which, again, means less power draw. All in all, people are VERY MUCH working on reducing on consumption reduction, which in turn means less heat, too.
The other is - the CPUs are mostly generating heat because their internals are not superconductors. HOWEVER, the technology they are made in very much influences this waste-heat effect, that's why a 32nm process is a LOT better than a 180nm process - even if you had literally the same transistor layout in there, the smaller components mean less resistance -> less heat. Manufacturing technology will also allow you to use lower voltages, which, again, means less power draw. All in all, people are VERY MUCH working on reducing on consumption reduction, which in turn means less heat, too.
Blogging about mobile linux - The Penguin Moves!
Maintainer of PyQt (see introduction and docs), AppWatch, QuickBrownFox, etc