New concept of paper battery developed by a CENIMAT/I3N team. The battery can be recharged in environments with just 40 percent humidity.This constitutes the first step towards future fully integrated self sustained flexible, cheap and disposable electronic devices, with great emphasis on the so-called paper electronics.
Check the following link to see how they are done
http://expresso.sapo.pt/como-e-fabricada-uma-bateria-de-papel=f627227
For the scientific papers please check
http://www.cenimat.fct.unl.pt/index.php?page=419&view=trabalho_cientifico:View&id=81
http://www.cenimat.fct.unl.pt/index.php?page=419&view=trabalho_cientifico:View&id=80