They will be incorporated into wearable gadgets first though

May 28, 2014 07:06 GMT  ·  By

Flexible electronics are seen as the next big “goal” of the technology industry, but there are always people looking at what will come after, namely high-tech clothing. Batteries that can make them happen may have just been invented.

A team of researchers from Fudan University in Shanghai, China, have designed and fabricated carbon nanotube (CNT) composite yarns.

Essentially, they took some carbon nanotubes and wound them onto a cotton fiber, basically inventing a sort of yarn that can store energy. The diameter of the yarn is 1 mm, making it possible to weave into cloth.

We don't really have to put that much effort into describing what sort of wonders this new invention can help create. After all, science fiction books, films and games have that well in hand.

It is believed that the Li-ion batteries that can be made from these fibers can have a pretty high charge and energy retention.

According to the study published in Nano Letters, the CNT fiber Li-ion battery has a high energy density of 0.75 mWh/cm and can retain 87% of its capacity after 100 cycles.

The Chinese team could have probably released something like this sooner, but the scientists had to dodge the silicon expansion problem first.

See, batteries produce energy via a chemical reaction, but silicon tends to swell by 300% while it's going on.

The Carbon nanotubes combined with the yarn create a new type of anode that buffers the volume change and keeps the silicon down in place. Otherwise, the silicon would expand and peel off, damaging the battery.

Meanwhile, the cathode is made of CNTs and lithium manganite, featuring high stability, working voltage and, one of the most important things, a low cost.

Finally, the CNT-based anode and cathode yarns (they're separated by a gel electrolyte) are wound together on a cotton fiber. And there you have it, the weavable Li-ion battery.

Sure, we may still have some years to wait before energy-generating and electronically enhanced clothing comes true. Between now and then, there are higher odds of the batteries being employed in super-thin and bendable smartwatches, wrist bands, arm bands, etc.

All in all, it's a promising but also surprising accomplishment. After all, many believed that supercapacitor fibers were the way to go, and Li-ion battery fibers had been mostly discounted due to being too difficult to fabricate.

All that's left is to further boost lifetime and charge strength, then it's on towards mass production. Making the threads color changing and self-powered will come after.