Increased electrochemical properties of ruthenium oxide and graphene/ruthenium oxide hybrid dispersed by polyvinylpyrrolidone

► A good dispersion of RuO2 and graphene/RuO2 is obtained by polyvinylpyrrolidone. ► PVP as a dispersant also can prevent the formation of metal Ru in graphene/RuO2. ► The max capacitances of the hybrid and RuO2 reach 435 and 597 F g−1 at 0.2 A g−1. ► The hybrid shows the best rate capability of 39% at 50 A g−1.