Lithium-ion batteries work by stacking active ingredients in layers. In your laptop and phone, the layers are stacked into a block, but a new process could make that seem quaint: spray-paint the needed layers onto any surface like paint, to make an instant battery anywhere.
Scientists at Rice Universitytested out distinct paints until they discovered a set that could work as the required components for a lithium-ion battery: two existing collectors, a cathode, an anode, and a polymer separator. The layers can be airbrushed on and the resulting battery is completely rechargeable. To test it out, researchers put it on steel, glass, ceramic bathroom tiles, and (why not?) a beer stein. Batteries on the bathroom tiles were in a position to send out a steady 2.4 volts–adequate to power light-emitting diodes that spelled out “Rice” for a complete six hours.
( via popsci.com )