A new superelastic battery holds particular promise for wearable technology.
Feature image and video credit: Chemistry World; YouTube
There’s no shame in my game: Stretchy pants—equally revered and reviled—are an integral part of my weekend uniform. Their elastic waistbands are forgiving in a way that denim (and weekdays) just can’t understand.
What if the bend and give of the perfectly aged pair of sweatpants could be replicated in the batteries that make our wearables work?
Thanks to a team of scientists from China’s Fudan University, it can.
Researchers have developed an incredibly elastic, high density lithium-ion battery that can be stretched up to 600 percent (far more than my stretchiest pair of stretchy pants).
How’d they do it?
According to a Chemistry World article, “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.” Their findings are published in the Journal of Materials Chemistry A.
Stretchable batteries aren’t exactly new, but the ability to develop batteries with “give” that are both safe and can be woven into increasingly small and lightweight wearables—particularly in clothing and textiles—is.
“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.
Their battery, which recorded a capacity of 91.3 mAh/g, was able to maintain that performance by more than 88 percent after being stretched by 600 percent. To see this super Li-ion do its thing, check out the video above.
The paper is “Super-stretchy lithium-ion battery based on carbon nanotube fiber,” (DOI: 10.1039/C4TA01878H).
What do you think of this super superelastic battery—and, in the interest of full disclosure, how do you feel about stretchy pants?