Created a “rubber” battery that can be bent, stretched and twisted
Researchers have used tensile materials to design a battery that can be bent, stretched, and twisted. Ideal for flexible electronics.
Manufacturers of smartphones, laptops, smart gadgets and sensors are paying more and more attention to elastic and foldable elements. However, they all need a power source, which is now usually a lithium-ion battery. Unfortunately, these batteries are heavy and rigid, which makes them difficult to use in flexible electronics or textiles..
Therefore, a team of scientists from the Swiss Higher Technical School of Zurich has developed a prototype of a flexible thin-film battery that can be bent, stretched and even twisted without disrupting the power supply. The team succeeds with the discovery of a new electrolyte.
The two current collectors for the anode and cathode consist of a flexible polymer composite that contains electrically conductive carbon and serves as an outer sheath. The inner surface of the composite is covered with a thin layer of microscopic silver flakes, stacked like a tile. When the elastomer is stretched, they continue to contact each other, which guarantees the conductivity of the current collector even with significant deformation..
In the event that the silver flakes do stop contacting, then an electric current can still flow through the carbon-containing composite, but more weakly..
The researchers then sprayed the anode and cathode powder onto a precisely defined area of the silver layer. The cathode consists of lithium manganese oxide and the anode is vanadium oxide.
At the last stage, the scientists laid two current collectors with electrodes on top of each other, separating them with a barrier layer similar to the picture frame, filling the gap in it with electrolyte gel. The developed gel electrolyte contains water with a high concentration of lithium salt, which not only facilitates the movement of Li ions between the cathode and anode, but also inhibits electrochemical decomposition..
Science Year 2 ~ Bend, squash, stretch and twist
Parts of the presented prototype were fastened with glue, but, according to the developers themselves, for commercial options it will be necessary to find another method of connection that will ensure tightness for a long period of time..
Recall that recently in Skoltech figured out how to make durable and fast-charging batteries.
text: Ilya Bauer, photo: ETH Zurich / Peter Rüegg