AsianScientist (Oct. 24, 2016) – Scientists in China have developed thin, flexible, lithium ion batteries with self-healing properties that can be safely worn on the body. Details were published in Angewandte Chemie.
Electronics that can be embedded in clothing are a growing trend. However, power sources remain a problem. Furthermore, while existing lithium ion batteries for wearable electronics can be bent and rolled up without any problems, they can break when they are twisted too far or accidentally stepped on—which can happen often when being worn. This damage not only causes the battery to fail, it can also cause a safety problem: Flammable, toxic, or corrosive gases or liquids may leak out.
A team led by Drs. Wang Yonggang and Peng Huisheng from Fudan University in Shanghai has now developed a new family of lithium ion batteries that can overcome such accidents, thanks to their self-healing abilities. In order for a complicated object like a battery to be made self-healing, all of its individual components must also be self-healing. Even after completely breaking apart, the battery can grow back together without significant impact on its electrochemical properties.
The electrodes in these batteries consist of layers of parallel carbon nanotubes. Between the layers, the scientists embedded the necessary lithium compounds in nanoparticle form (LiMn2O4 for one electrode, LiTi2(PO4)3 for the other). In contrast to conventional lithium ion batteries, the lithium compounds cannot leak out of the electrodes, either while in use or after a break.
After a break, it is only necessary to press the broken ends together for a few seconds for them to grow back together. Also, the capacity and charging and discharging properties of a battery ‘armband’ placed around a doll’s elbow were maintained, even after repeated breaking and self-healing cycles.
The article can be found at: Zhao et al. (2016) A Self-Healing Aqueous Lithium-Ion Battery.
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Source: Angewandte Chemie.
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