Design, synthesis and the electrochemical performance of MnO2/C@CNT as supercapacitor material

Abstract Carbon-coated carbon nanotubes (C@CNT) was designed, synthesized and used as conductive substrate for loading manganese dioxide to prepare MnO 2 /C@CNT composite. C@CNT with self-sacrificial carbon layer as protection is suitable for loading higher content of MnO 2 . The morphology and microstructure of the as-prepared MnO 2 /C@CNT composite with MnO 2 loading up to 78 wt% were investigated by SEM and TEM. The electrochemical performance of MnO 2 /C@CNT was evaluated by cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) method. With the protective carbon layer on the surface of CNTs, MnO 2 /C@CNT composite presents superior specific capacitance of 227 F/g with MnO 2 loading up to 78 wt% at a current density of 0.2 A/g and good cyclic stability with 94% of its maximal specific capacitance maintained after 1000 CV scans.