Wearable electronics attract remarkable attention both in academia and industry because of their wide application such as smart textiles with built-in electronic functions. All wearable electronic devices require lightweight, wearable and high-performance energy-storage components to provide power. Regarding these requisitions, developing fabric-based energy-storage devices is an ideal solution because textile fabrics exhibit intrinsically mechanical flexibility, lightweight, high surface area and most importantly, the feasibility of device integration into wearable forms. Among many energy-storage devices, a supercapacitor shows distinctive advantages due to its high power density, fast charge/discharge capability, excellent reversibility, long cycle life and safety, which are very suitable for wearable applications.
Therefore, we report herein a cost-effective and continuous one-step electrospinning method for directly fabricating the flexible and wearable supercapacitor fabrics. The key novelty of our method is to use the wearable nickel-coated cotton fabric as a conductive collecting substrate, on which a high concentration of multi-walled carbon nanotubes (MWCNTs) can be directly electrospun to form a thin carbon nanofiber web on metallic fabric at the room temperature, without the need for any post-treatment. This enables the formation of an interconnected MWCNT framework through the electrospun nanofiber web, ensuring the high electrical conductivity and ion accessibility of the as-made fabric electrode. Supercapacitor fabrics assembled with these as-made electrodes can show good electrochemical performances and more importantly, can be easily integrated into wearable forms by using simple and conventional sewing technology. Considering the wide accessibility, high scalability and good variability of the electrospinning technique, we believe that there still exists a large room for improving the performance of the supercapacitor fabrics, which are very likely to become ideal integrated energy-storage devices for next-generation wearable electronics.