by Shane Henson — July 16, 2012—Researchers at Rice University have developed a lithium-ion battery that can be painted on virtually any surface, a game-changing creation that will allow all kinds of new design and integration possibilities for storage devices.
The rechargeable battery created in the lab of Rice materials scientist Pulickel Ajayan consists of spray-painted layers, each representing the components in a traditional battery. Each layer is “an optimized stew.” The research has been published in Nature’s online, open-access journal Scientific Reports.
“There has been lot of interest in recent times in creating power sources with an improved form factor, and this is a big step forward in that direction,” said Ajayan.
Lead author Neelam Singh, a Rice graduate student, and her team spent painstaking hours formulating, mixing and testing paints for each of the five layered components—two current collectors, a cathode, an anode and a polymer separator in the middle. The materials were airbrushed onto ceramic bathroom tiles, flexible polymers, glass, stainless steel and even a beer stein to see how well they would bond with each substrate.
The researchers reported that the hand-painted batteries were remarkably consistent in their capacities, within plus or minus 10% of the target. They were also put through 60 charge-discharge cycles with only a very small drop in capacity, Singh said.
Singh said the batteries were easily charged with a small solar cell. She foresees the possibility of integrating paintable batteries with recently reported paintable solar cells to create an energy-harvesting combination that would be hard to beat. As good as the hand-painted batteries are, she said, scaling up with modern methods will improve them by leaps and bounds.
The Rice researchers have filed for a patent on the technique, which they will continue to refine. Singh said they are actively looking for electrolytes that would make it easier to create painted batteries in the open air, and they also envision their batteries as snap-together tiles that can be configured in any number of ways.
