Bendable lithium-air battery inspired by Chinese calligraphy
Tue 26 Jan 2016
Chinese scientists have developed a new flexible, bendable lithium-based battery, inspired by the ancient art form calligraphy.
As global demand for flexible components grows in such markets as IoT and wearables, so too does the need for battery equipment to flex in the same way. Now, a research team based at the Changchun Institute of Applied Chemistry has designed a flexible lithium-air battery, using Chinese brush painting as its inspiration.
While lithium-ion batteries are able to power most portable electronic devices, such as smartphones and laptops, they are dwarfed in energy density by lithium-air batteries which can hold up to 10 times more energy than a lithium-ion battery of the same weight.
‘Non-aqueous Li–O2 batteries have been developed due to their extremely high energy density […] Therefore, the development of flexible Li–O2 batteries is urgently desirable to meet the high energy density requirements of next-generation flexible electronic devices,’ wrote senior study author Xinbo Zhang, a materials scientist at the institute.
Batteries typically consist of two electrodes – an anode and a cathode. In the case of a lithium-air battery, the anode usually contains lithium metal, whereas the cathode is generally made of a porous carbon material which allows air to reach inside the battery. Electricity is generated when the lithium is exposed to the oxygen, and recharging the device reverses this process.
In the study, titled Flexible and Foldable Li–O2 Battery Based on Paper-Ink Cathode and published in December’s edition of Advanced Materials, the team explained that the main component of the painting ink used in calligraphy is carbon and as paper is made of porous, thin fibres, the combination could provide a flexible and inexpensive cathode alternative.
The researchers experimented by layering the new ink-paper cathode and a lithium-foil anode either side of a sheet of glass fibres which allows the electrically charged ions to flow between the two electrodes.
Zhang and the team found that, even after 1,000 flex cycles, their calligraphy battery was able to achieve energy capacities similar to commercially available lithium-ion batteries. The sandwiched materials could also be folded easily to create battery packs.