According to a report from Rice University, researchers there have developed a battery that can literally be painted onto surfaces. The researchers present their proposal in a paper published by Nature Scientific Reports.
To test the operation of the batteries, the researchers applied the paintable battery layers to nine ceramic bathroom tiles and connected them in parallel. They added a solar cell which was able to convert the laboratory’s light into current. With the solar-panel’s light and house current, the researchers were able to fully charge the tile-based battery, which were then able to produce enough current to power a series of light-emitting diodes which spelled “RICE”. The battery generated a current of 2.4 volts, and kept the diodes lit for six hours. The researchers also noted that they were able to drain and recharge the batteries sixty times with very little loss of capacity.
The paintable lithium-ion battery consists of five layers: a cathode, and anode, two current collectors, and a separator. In a series of tests, the team, led by paper lead author Neelam Singh, applied the layers of the battery to a number of various surfaces, including ceramic tiles, flexible polymers, steel, and glass. Singh notes that the hardest challenge was getting the layers to reliably adhere to the surfaces to which they were applied. “We found that the nanotube and the cathode layers were sticking very well, but if the separator was not mechanically stable, they would peel off the substrate.” Singh’s team had to find the right mixture of compounds to give the separator the adhesion necessary to keep the battery layers bound to the surface. After the layers were painted, the layers were heat-sealed for further stability.
Singh is also optimistic about taking the new technique out of the laboratory, saying “Spray painting is already an industrial process, so it would be very easy to incorporate this into industry.” She hopes that the new technology could lead to inventive new applications battery-provided power, and notes especially that the paintable batteries could be combined with new flexible and paintable solar panels to produce nearly autonomous power support. Lab director and Rice materials scientist Pulickel Ajayan notes, “This means traditional packaging for batteries has given way to a much more flexible approach that allows all kinds of new design and integration possibilities for storage devices.” Singh adds, “We really do consider this a paradigm changer.”
The researcher was supported by the Advanced Energy Consortium, the National Science Foundation, Army Research Laboratories, and Nanoholdings Inc.