Interface Engineering of Carbon Fiber-Based Electrode for Wearable Energy Storage Devices

Carbon-based fibrous supercapacitors (CFSs) have demonstrated great potential as next-generation wearable energy storage devices owing to their credibility, resilience, and high power output. The limited specific surface area and low electrical conductivity of the carbon fiber electrode, however, impede its practical application. To overcome this challenge, this study fabricated a CFS by sequentially coating graphene, carbon nanotube, and activated carbon on the carbon fiber surface (CF/G/CNT/AC). The CF/G/CNT/AC exhibited excellent electrochemical performance with a specific capacitance of 692 mF cm^–2 at 70 μA cm^–2 and good cycling stability over 4000 cycles. This result is ascribed to the increase of contact area between the active material and the current collector. Moreover, the energy density of the as-prepared CF/G/CNT/AC fibrous supercapacitor reaches 86.6 and 37.7 μW cm^–2 at power densities of 126 and 720 μW cm^–2, respectively, demonstrating its potential for practical applications. In addition, the CF/G/CNT/AC demonstrated favorable traits such as mechanical flexibility, feasibility, and energy storage capacity, qualifying it as a viable alternative for wearable electronic textiles. Graphical abstract: [Figure not available: see fulltext.].