Scientists at Rice University Develop a Spray-On Battery

An electron microscope image of a spray-painted lithium-ion battery developed at Rice University shows its five-layer structure. Photo courtesy: REUTERS/Ajayan Lab/Rice University/Handout

Scientists in the United States 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 at Rice University in Houston, Texas, 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.

A beer stein served as an able substrate for a paintable battery developed at Rice University. Photo courtesy: REUTERS/Jeff Fitlow/Rice University/Handout

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.

The researchers are looking for components that would allow construction in the open air for a more efficient production process and greater commercial viability.

Neelam Singh, who worked on the project, believes the technology could be integrated with solar cells to give any surface a stand-alone energy capture and storage capability.

The researchers tested the device using nine bathroom tiles coated with the paint and connected to each other. When they were charged, the batteries powered a set of light-emitting diodes for six hours, providing a steady 2.4 volts.

The results of the study were published on Thursday in the journal Nature Scientific Reports.