Ruthenium Oxide/Reduced Graphene Oxide Nanoribbon Composite and Its Excellent Rate Capability in Supercapacitor Application

Chemical oxidation is used to cut and unzip multi‐walled carbon nanotubes in the transverse direction and the axial direction to form graphene oxide nanoribbon (GONR). Ruthenium oxide/reduced graphene oxide nanoribbon composite (RuO 2 /rGONR) with a 72.5 wt% RuO 2 loading is synthesized through an aqueous‐phase reaction, in which GONR is served as starting material, followed by mild thermal treatment in ambient air. The resulting RuO 2 /rGONR composite achieves specific capacitance up to 677 F·g −1 at the current density of 1 A·g −1 in three‐electrode system using 1 mol·L −1 H 2 SO 4 as electrolyte. The resultant electrode exhibits an excellent rate capability (91.8% retention rate at 20 A·g −1 ). Especially, the symmetric supercapacitor assembled on the basis of RuO 2 /rGONR electrode delivers high energy density (16.2 Wh·kg −1 ) even at the power density of 9885 W·kg −1 , which is very essential for supercapacitors.