Scientists Develop Stretchable Battery That Can Be Washed
Scientists from the University of British Columbia have developed a battery that functions when twisted, stretched to twice its length, and even after being tossed in the washing machine.
While the battery isn't the first battery that can be stretched, it is the first that can be washed repeatedly without suffering any degradation. The breakthrough could help boost wearable technology that can handle the rigors of everyday use.
"Wearable electronics are a big market, and stretchable batteries are essential to their development," states Dr. Ngoc Tan Nguyen, lead author of the recent paper "Washable and Stretchable Zn-MnO2 Rechargeable Cell. "However, up until now, stretchable batteries have not been washable. This is a critical addition if they are to withstand the demands of everyday use."
Standard batteries feature internal layers of hard materials encased in a rigid exterior, which prevents them from bending and damaging the internal structure. To design their stretchable battery, the scientists created key compounds, including zinc and manganese dioxide, ground them into small pieces, then added them to a rubbery polymer.
The battery contains several layers of the metal-infused polymer wrapped inside of a case made from the same material, which is air-tight, waterproof and can be used repeatedly in everyday use. The team then threw the battery in the wash to test the seal and found it was still going strong after 39 wash cycles.
The choice of materials also helps protect the wearer as lithium-ion battery chemistry tends to become toxic and flammable when damaged. The scientists are currently working to raise the battery's power output and cycle life, and some commercial manufacturers are already interested in using the technology in their next-gen devices. The researchers also note that when the battery becomes available to the general public, it will cost the same as ordinary rechargeable batteries.