Is there anything more unfortunate for our species than the invention of the chemical battery? In terms of energy density, longevity, and charge time, they're basically the worst energy storage format you could dream of. I'd rather have a cell phone with a tiny disc-shaped flywheel inside, capable of storing twice the energy of a battery and lasting forever with no degradation in performance.
I'd rather have a phone that runs on butane, which is at least 10x more energy dense than a battery. Imagine your phone lasting a week between charges and it could be refilled in 25 seconds from a portable butane canister or from a small hose coming from your wall.
I'd rather have a phone that runs on a small tank of compressed air, greater energy density than a battery and more longevity in the components.
I'd rather have a phone that ships from the factory with a non-removeable piece of uranium the size of a grain of sand, which would probably be enough to keep it on for a decade straight.