Scientists unveil lithium ion battery for wearable electronics that can be twisted and stretched 600 percent
Lithium ion batteries that can be stretched by 600% have been unveiled by scientists in China. In the future, the fibre shaped batteries could be woven into textiles to satisfy the ever-growing requirement for wearable devices.
Huisheng Peng and colleagues at Fudan University made the superelastic batteries by winding two carbon nanotubes–lithium oxide composites yarns, which served as the positive and negative electrodes, onto an elastomer substrate and covering this with a layer of gel electrolyte. The batteries owe their stable electrochemical performance under stretching to the twisted structure of the fibre electrodes and the stretchability of the substrate and gel electrolyte, with the latter also acting as an anchor. When the batteries were stretched, the spring-like structure of the two electrodes was maintained.
Previous stretchable batteries have generally been produced in a planar format, which has been an obstacle for their development for small, lightweight, wearable electronics. ‘Our fibre-shaped batteries can easily be scaled-up to an appropriate length and woven into clothing that can adapt to the body’s movement,’ says Peng.