I’ve just come across this (admittedly rather old) news article which I think is really quite exciting. Sony have developed a new prototype paper-powered battery which could allow customers to use their products (including mobile phones) by using waste paper-powered batteries. Shredded paper is turned into sugar using enzymatic processing and the resulting sugars then become a source of fuel.
The full article can be read here: http://www.bbc.co.uk/news/technology-16288107
How great would that be, no more batteries leaking out corrosive chemicals on landfill waste sites.