Paintable and printable solar cells are lowering the cost of solar power, and now researchers at Rice University have come up with a battery to match. They have developed a new paintable lithium-ion battery that can be applied to almost anything from beer mugs and bathroom tiles to plastics, glass and steel. Since the new battery can be charged with a small solar cell, the team envisions low cost, paint-on devices that can harvest solar energy and store it for later use, too.
Painting with Batteries
The new technology is based on separating the components of the battery into five paintable solutions, like a high tech paint-by-numbers kit.
The positive current collector is based on carbon nanotubes, and the cathode contains lithium cobalt oxide. A third component is a polymer separator made with a proprietary resin called Kynar Flex (made by the company Arkema).
The anode contains lithium titanium oxide, and the negative current collector is based on an off-the-shelf copper paint.
That sounds simple enough, but the team found that getting the right properties to make the separator stick on was the tricky part.
Low Cost Solar Batteries on the Way
The team really did test the paint-on battery on a beer stein along with other common objects such as bathroom tiles, and they were able to power a light with it after charging the battery on either white light or the lab current.
The research-scale product was hand painted, but lead author and researcher Neelam Singh points out that it would be fairly easy to scale up the technology to commonly used industrial spray-painting techniques.
One key to lowering the cost of the technology will be to develop paintable solutions that can be applied in open conditions, rather than relying on vacuum deposition technology or other intensely controlled environments.
The New Energy Aesthetic
If solar inks and other liquid solar power technologies develop apace with paintable batteries, it’s likely to lead to a new generation of options for architecture, interior design and product design, in which objects and surfaces can be used to harvest energy, store it and power lights and other devices.
The possibilities really multiply when combined with ultra-efficient lighting, namely OLED (organic light emitting diode) technology, which enables the creation of entire light-integrated surfaces.
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Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.