RGO/KMn8O16 composite as supercapacitor electrode with high specific capacitance

Reduced graphene oxide/cryptomelane (RGO/KMn8O16) composites are successfully synthesized from alpha-MnO2 nanorods and GO using a water-bathing precipitation method. The unique structure of KMn8O16 nanorods, with a length of 2-4 mu m, dispersed on the surface of RGO leads to a much enhanced electrical conductivity and ionic transport, finally achieving composites with an improved electrochemical performance. Electrochemical measurement results show a specific capacitance of 222.3 F/g at a current density of 0.2 A/g, much higher than that of the original alpha-MnO2. After 500 cycles at 2.0 A/g, the RGO/KMn8O16 composite electrode still retains 92.6% of its initial specific capacitance. The excellent electrochemical performance and durability observed for this composite electrode suggest its potential application for electrochemical capacitors. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.