▎ 摘　　要

Introducing oxygenated functionalities into carbon networks can provide additional pseudocapacitance for supercapacitors. However, excessive and unstable oxygen functional groups usually cause low electrical conductivity and rate performance. Herein, we propose a novel and simple strategy for tunable functionalization of edge-enriched graphene nanoribbons by means of dielectric barrier discharge (DBD) plasma. The functionalized graphene nanoribbons from DBD plasma exhibit high specific capacitance owing to the suitable oxygen functional groups and the intrinsic edge-enriched structure. The assembled symmetric supercapacitor device based on as-prepared graphene nanoribbons with oxygenated functionalities exhibits a superior energy density of 12.65 Wh kg(-1), and 93.76% capacitance retention after 10,000 cycles in 1 M Na2SO4 aqueous electrolyte. This work may find a new way to finely control functionalities on carbon nanomaterials for high-performance energy storage devices. (C) 2020 Elsevier Ltd. All rights reserved.