Plasma treated carbon nanofiber for flexible supercapacitors

Abstract

Ambient plasma is applied to carbon nanofiber (CNF) and investigated for flexible supercapacitor applications. For the flexible supercapacitor applications, gel electrolyte and nickel foam as a supporting collector electrode were used. The plasma treatment increases active surface area of CNF by three times and decreases electrochemical charge-transfer resistance dramatically from 9.5 to 3.7 Ω. Resultant capacitances of 210 ± 3 Fg−1 and 129 ± 1 Fg−1 (0.5 Ag−1) in three-electrode system and two-electrode system, respectively, are obtained with high specific energy of 11.5 Whkg−1 and specific power of 200 Whkg−1. Finally, it shows reliable flexibility as well as high specific capacitance retention (84%) and coulombic efficiency (81%) after 10,000 cycles. The result demonstrates that the as-prepared materials may be suitable for flexible all-solid-state supercapacitor devices.