Battery technology keeps improving in terms of density and storage, but how about changing the very form in it which a battery is presented? This is what researchers at Rice University in Texas have done with the creation of a paintable battery solution that reinvents the whole concept.
The rechargeable battery consists of spray-painted layers, each representing the components in a traditional battery. The research was carried out in the laboratory of materials scientist Pulickel Ajayan and it has the potential to turn any surface into a lithium-ion battery, which could be a real game-changer when combined with solar cells.
Lead author Neelam Singh, a Rice graduate student, and her team spent a great deal of time 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 mug to see how well they would bond with each substrate.
In the first experiment, nine bathroom tile-based batteries were connected in parallel. One was topped with a solar cell that converted power from a white laboratory light. When fully charged by both the solar panel and house current, the batteries alone powered a set of light-emitting diodes that spelled out “RICE” for six hours. The batteries provided a steady 2.4 volts.
Singh said the batteries were easily charged with a small solar cell. She foresees the possibility of integrating paintable batteries with paintable solar cells to create a killer energy-harvesting combination. Besides, since spray painting is already an industrial process, “it would be very easy to incorporate this into industry,” she said.
The Rice researchers have filed for a patent on the technique, which they will continue to develop and refine. Singh said they are looking for electrolytes that would make it easier to create painted batteries in the open air. They also envision their batteries as snap-together tiles that can be configured in any number of ways.