Wearable Batteries
On November 14, KAIST EEWS Graduate School Professors Choi Jang-wook and Lee Jeong-yong, and Professor Kim Taek-soo of the Mechanical Engineering Department, announced they have successfully developed a new concept battery that can be bent, folded, and charged with solar power.
Recently, with the release of Samsung’s Galaxy Gear, Apple’s iWatch, and Google’s Google Glass, technological competition is rising for domination of the wearable device market.
The research team focused on applying flexibility to batteries based on fabric used for clothes, and how it doesn’t change regardless of repeated movements.
First, polyester fabric was plated with nickel. Then as an electrode active material for each pole, a thin layer of lithium-phosphoric acidic iron oxide on the positive side, and lithium-titanium oxide on the negative side have been coated for a flexible collector. This collector maintains the fabric’s flexibility, allowing bending, folding, and wrinkling. This improves on the original battery collector made of aluminum and copper, which easily broke after a few bends.
In fact, the three-dimensional fabric structure used as the collector’s frame allows power to be distributed equally regardless of repetitive movements, making the battery function smoothly even after folding 5,000 times. The collector will soon be applied to various wearable sectors after a future optimization process, such as showing 2V voltage and 85mAh capacity.
This battery can be used with organic solar cells, which allows it to be worn and wrinkled like clothes while charging with solar power. This research has been published in the “Nano Letters” (online, on the 5th) which is a global publication of the nanotechnology sciences.
Professor Choi said, “Using this battery, wearable computer technologies will gain some momentum. If applied to outdoor clothing, this battery can develop clothes that can make people sweat in the winter,” and added, “It will contribute greatly to a new IT generation, with people wearing several small mobile electronic devices.”