Scientists have developed a paint that can store and deliver electrical power just like a battery.
Traditional lithium-ion batteries power most portable electronics. They are already pretty compact but limited to rectangular or cylindrical blocks.
Researchers have come up with a technique to break down each element of the traditional battery and incorporate it into a liquid that can be spray-painted in layers on virtually any surface.
"This means traditional packaging for batteries has given way to a much more flexible approach that allows all kinds of new design and integration possibilities for storage devices," said Pulickel Ajayan, who leads the team on the project.
The rechargeable battery is made from spray-painted layers, with each representing the components of a traditional battery: two current collectors, a cathode, an anode and a polymer separator in the middle.
The paint layers were airbrushed onto ceramics, glass and stainless steel, and on diverse shapes such as the curved surface of a ceramic mug, to test how well they bond.
One limitation of the technology is in the use of difficult-to-handle liquid electrolytes and the need for a dry and oxygen-free environment when making the new device.