RuO2/MnO2 core–shell nanorods for supercapacitors

Abstract

RuO₂/MnO₂ NRs as an electrode for supercapacitors show a high electrochemical performance with a specific capacitance of 793 F g⁻¹ (based on MnO₂) by cyclic voltammetry (CV) at a scan rate of 2 mV s⁻¹ in 1 M Na₂SO₄ aqueous solution. A good rate capability with a specific capacitance of 556 F g⁻¹ at a current density of 1 A g⁻¹ and a good cycling stability (20% degradation after 1000 cycles) were also achieved. The enhancement of capacitive behavior can be attributed to the conductive RuO₂ template with a series resistance of 0.75 Ω and a charge transfer resistance of 0.75 Ω. The results show that an active material such as a MnO₂ hybrid with highly conductive 1D nanowires may greatly improve the electrochemical performance for supercapacitors.