Graphene/Conducting Polymer Composite Fibers for Wearable Energy Storage

The advent of new electrode materials, particularly in the form of fibers, has enabled creative approaches to the fabrication of novel electrochemical cell configuration. Recently, fiber-shaped supercapacitors have attracted significant attention as wearable energy storage due to their ability to be woven or knitted into fabrics, or stitched into existing textiles. Long lengths of fiber electrodes are crucial to fabricate such fiber-shaped supercapacitors. Here, we report covalently bonded graphene fibers with high conductivity and mechanical strength through a wet-spinning method. Meters long fibers can be produced in a couple of hours. Conducting polymers, such as polypyrrole or polyaniline, are deposited on the graphene fibers to enhance the capacity using an electrochemical polymerization method. Two composite fibers are coated with polymer electrolyte and twisted together to form a solid-state supercapacitor. The fabricated supercapacitor shows good electrochemical performance and excellent flexibility, which make itself an ideal candidate as wearable energy storage device to be integrated into garments.