The trouble with new battery developments is that the driving force is increased power density. That is the opposite of safety. With lithium batteries, the power density is already similar or even higher than some explosives. The time will come when the power storage capacity of devices has to be limited and not just for aviation safety. So manufacturers will have to do more work on efficiency. Maybe future mobile devices will have to be plugged to an external supply to realise their full potential in terms of processing speed and screen brightness. That would be progress
