Ink on paper can act as an electrode in a thin, flexible battery.

Credit: Adv. Mater./Xin-Bo Zhang et al. (Colour Version)

Inspired by Chinese brush painting, a team led by Xin-Bo Zhang at the Chinese Academy of Sciences' Changchun Institute of Applied Chemistry fabricated a flexible lithium-air battery using lithium foil and paper with a carbon-based ink (pictured). Electrons are stripped from the foil, creating lithium ions that flow to the inked paper electrode, where they combine with oxygen from the air. The resulting battery can hold a charge even after it has been bent 1,000 times. A foldable pack of four batteries, which weighs less than 2 grams, can supply current for 100 hours.

The technique paves the way for cheap and easily manufactured flexible batteries, the authors say.

Adv. Mater. (2015)