Chinese scientists have developed a portable power source that can be woven into materials like cotton.
Scientists at Fudan University in Shanghai have developed battery technology that can be woven into fabrics like cotton.
The researchers, Wei Wang and his colleagues, created a lithium ion battery fiber by designing and developing carbon nanotube (CNT) composite yarns that are wound around a cotton fiber. The fibers have a diameter of about 1mm and can be woven into textiles or fabrics and can be easily integrated into flexible wearable technology products.
According to Wei Wang, the fiber lithium ion battery can be used as a power source for wearable electronics. Creating a good power source that can be directly and seamlessly integrated into wearable tech devices has always been something that developers are interested in and a power source that can be woven into fabrics holds a lot of potential. The fiber lithium-ion battery can become key to developing new wearable electronics that wouldn’t require a separate and bulky power source or extra compartments for batteries. The new type of batteries can also be potentially used in other industries and machines – as carpets or seats for automobiles, for example.
To create the battery, the scientists used carbon nanotube to make a composite CNT and silicon yarn anode to deal with the silicon expansion issue that comes with trying to create a lithium ion battery fibers. The carbon nanotubes effectively buffer the change in volume of the silicon during the charging-discharging process. The CNT-silicon structure prevents damage to the battery due to the silicon expansion.
The scientists also used CNT and lithium manganite to create the cathode. The CNT-based anode and cathode yarns — separated by a gel electrolyte — are wound together onto a cotton fiber to create the CNT fiber lithium-ion battery.
The CNT fiber lithium-ion battery has exhibited good electrochemical properties, including an energy density of 0.75 mWh/cm and a capacity retention of 87 % after 100 cycles.
The researchers admit that further work still has to be done to improve the battery. They plan to not only try to improve the performance of the battery, but also work on large-scale production and the addition of other characteristics like color-changing ability and stretchability.
The study was published in Nano Letters last May.