Let me just start off by voicing a general sense of wariness with new Lithium-ion technology in general. While there are tons and tons of articles about new anode and cathode technology, slimmer batteries, and differing compoundsโฆ most of the tech has been theoretical, or at the very least, impractical to mass produce. Iโm going to say that this most recent paintable lithium-ion battery technology, which can turn virtually any surface into a lithium-ion battery, also falls into that category. But itโs still cool โ and perhaps someday weโll see some of this tech get practical and come to fruition. Which brings us to this weekโs lithium-ion advancement: researchers at Rice University have developed a lithium-ion battery that can literally be painted on the surface of any object.
Paintable Lithium-ion Battery Technology Features
The rechargeable battery was created in the lab by Rice materialsย scientist Pulickel Ajayan and consists of spray-painted layers, eachย representing the anode and cathode components of a traditional battery. The researchย appears in Natureโs online, open-access journal Scientific Reports. The implication is that traditional packaging for batteries could give way to new design andย integration possibilities for storage devices. Your batteries could be integrated into the very products they power. Forget form factor, the batteries could BE the tools.
Lead author Neelam Singh, a Rice graduate student, and her team spentย painstaking hours formulating, mixing and testing paints for each ofย the five layered components โ two current collectors, a cathode, anย anode and a polymer separator in the middle. The materials were airbrushed onto ceramic bathroom tiles, flexibleย polymers, glass, stainless steel and even a beer stein to see how wellย they would bond with each substrate.
In the first experiment, nine bathroom tile-based batteries wereย connected in parallel. One was topped with a solar cell that convertedย power from a white laboratory light. When fully charged by both theย solar panel and house current, the batteries alone delivered 2.4 volts and powered a set ofย light-emitting diodes that spelled out โRICEโ for six hours.
The researchers reported that the hand-painted batteries wereย remarkably consistent in their capacities, within plus or minus 10ย percent of the target. They were also put through 60 charge-dischargeย cycles with only a very small drop in capacity, Singh said.
The multi-layer painted-on system is actually pretty interesting. The first layer is the positive currentย collector. The second layer isย the cathode. The third is the polymerย separator paint. The fourth layer is the anode, a mixture of lithiumย titanium oxide and UFG in a binder. The final layer is the negativeย current collector, a commercially available conductive copper paint,ย diluted with ethanol.
Singh said the batteries were easily charged with a small solar cell.ย She foresees the possibility of integrating paintable batteries withย recently reported paintable solar cells to create an energy-harvestingย combination that would be hard to beat. As good as the hand-paintedย batteries are, she said, scaling up with modern methods will improveย them by leaps and bounds. โSpray painting is already an industrialย process, so it would be very easy to incorporate this into industry,โย Singh said.
The Rice researchers have filed for a patent on the technique, whichย they will continue to refine. Singh said they are actively looking forย electrolytes that would make it easier to create painted batteries inย the open air, and they also envision their batteries as snap-togetherย tiles that can be configured in any number of ways.
I, for one, would love to think that we could one day go to the store and pick up a 5-can spray pack to produce a rechargeable lithium-ion battery that would power a particular device of our choosing.
Of course, that might be something more for my grandkidsโฆ but who knows.
