Hierarchically nanostructured carbon fiber-nickel-carbon nanotubes for high-performance supercapacitor electrodes

This work demonstrates the fabrication of micro carbon fibers with hierarchical nanostructures of nickel-carbon nanotubes by electroless plating and chemical vapor deposition. Characterizations show that the micro coaxial fibers have 1400 times larger surface area, and 100 times larger electrochemical capacitance than pristine carbon fibers, while their mechanical strength has only 8% degradation. These outstanding properties make the micro coaxial fibers promising for applications in flexible or wearable supercapacitor electrodes. •A hierarchical carbon fiber-nickel-carbon nanotubes coaxial structure was fabricated.•The coaxial micro fiber has much better electrochemical performance than pristine carbon fiber.•The coaxial micro fiber remains good tensile strength compared with the pristine carbon fiber.