Anchoring Hydrous RuO 2 on Graphene Sheets for High‐Performance Electrochemical Capacitors

Abstract Hydrous ruthenium oxide (RuO 2 )/graphene sheet composites (ROGSCs) with different loadings of Ru are prepared by combining sol–gel and low‐temperature annealing processes. The graphene sheets (GSs) are well‐separated by fine RuO 2 particles (5–20 nm) and, simultaneously, the RuO 2 particles are anchored by the richly oxygen‐containing functional groups of reduced, chemically exfoliated GSs onto their surface. Benefits from the combined advantages of GSs and RuO 2 in such a unique structure are that the ROGSC‐based supercapacitors exhibit high specific capacitance (∼570 F g −1 for 38.3 wt% Ru loading), enhanced rate capability, excellent electrochemical stability (∼97.9% retention after 1000 cycles),…