Spray-on batteries could power your future laptop

One day, your walls might be able to power your laptop: Researchers at Rice University have developed a new type of spray-on lithium-ion battery that can be literally painted on nearly any surface.

Rice University graduate student Neelam Singh headed the "Paintable Battery" study to develop a battery that can be assembled on any wall like a multi-coat paint job. The difference is that, instead of applying a primer and base coat, you would assemble a power cell using various spray-on components.
The battery paint consists of five layers of components that include a carbon-nanotube-based positive current collector, the cathode, a polymer separator, an anode, and a negative current collector made of conductive copper paint that completes the circuit.

The scientists successfully airbrushed their battery paint onto a number of surfaces, including ceramic bathroom tiles, flexible polymers, glass, stainless steel, and even a beer stein. What makes it even better is that the paint actually stores and discharges electricity as a regular energy cell would.

In the team's first experiment, the scientists applied the paint battery to nine bathroom tiles connected to a small LED array that spelled "RICE." The batteries alone powered the lights for six hours straight with a steady 2.4 volts. Furthermore, the batteries proved to be long-lasting, having suffered little capacity degradation even after 60 recharging cycles.

The team's research appears in a paper published in Nature co-authored by Rice graduate students Charudatta Galande and Akshay Mathkar, Rice research scientist Arava Leela Mohana Reddy, Rice Quantum Institute interns Andrea Miranda and Alexandru Vlad, and Los Alamos National Laboratory postdoctoral researcher Wei Gao.
The Rice researchers have filed for a patent on their battery paint technique, which they will continue to refine. The team hopes to find new electrolytes that can be easily applied in an open-air environment rather than a closed-off laboratory.

Singh envisions that the technology could be integrated with paintable solar cells. She also sees the possibility that the technology could go commercial like solar panels have with snap-together battery tiles.

[Rice University and Nature via CNET]