But for the process to result in a working battery, all five layers must stick together and work in synchrony, and the tricky step was finding a separator material that kept the whole stack in one piece.

BBC: 'Paint-on' batteries demonstrated

We are also working on battery charging stations and smart grids.

FORBES: Behind BYD's Success With Chinese Customers

Boeing is working to replace battery systems that are believed to have been behind fires on two 787s run by Japanese airlines in January.

BBC: US lifts Boeing Dreamliner ban