Fiber-Shaped Electrochemical Capacitors Based on Plasma-Engraved Graphene Fibers with Oxygen Vacancies for Alternating Current Line Filtering Performance

Rapid advances in flexible and wearable electronics have enhanced demand for electrochemical capacitors (ECs) with fast frequency responses and supernal electrochemical supercapacitive properties. Here, we report the development of a fiber-shaped supercapacitor device based on Ar plasma-treated, highly electrically conductive reduced graphene oxide (rGO) fibers. Typical rGO-based, fiber-shaped ECs exhibit ultrafast frequency responses (phase angle = ？81.1°), a short resistor–capacitor (RC) time constant (0.471 ms at 120 Hz), and excellent cycle stability. The superior performance of our device relative to most advanced carbon-based ECs is promising for alternating current line filtering performance