Electroless Deposition Assisted CuO/Carbon Fiber Nanohybrids for Fiber Supercapacitors

A rapid growth in wearable technology is accelerating the advent of next generation of wearable electronics, which will become even more wearable and functional. Before this advance, however, the development of one-dimensional (1-D) flexible energy storage devices which can be woven into textile forms favorable to direct integration with wearable electronics is essential. To this end, many researchers have extensively studied fiber-type supercapacitors because when compared to batteries, supercapacitors exhibit higher power density, longer cycle life, and better safety. Inspite of these merits of supercapacitors, a scalable and facile synthetic route for fabrication of 1-D electrodes is still limited. In addition, low energy density of supercapacitors must be overcome for their practical use. In this work, we used carbon fibers as both a current collector and template for electroless deposition of copper. After thermal treatment, the carbon fibers were continuously coated with multifaceted copper oxide, leading to increase of the surface area. Moreover, with the aid of pseudo-capacitive behavior of copper oxide, the energy density of our fiber-type supercapacitor was highly improved, compared to carbon fibers only. Our approach offers a scalable, robust synthetic pathway to prepare CuO/carbon fiber composites for supercapacitor electrodes via electroless deposition.