Design and synthesis of hierarchical porous electrode with nanocomposites of MnO2 thin layer encapsulated carbon nanotubes and its superb charge storage characteristics

Three-dimensional hierarchical porous electrode with nanocomposites of MnO2 thin layer encapsulated carbon nanotubes (CNTs) was achieved. Scanning electron microscopy images displayed that the whole surface of CNTs was completely coated with uniform MnO2 thin layer leading to a novel encapsulated structure with CNTs core and MnO2 shell. The as-prepared electrode presented a superb charge storage characteristic with large specific capacitance of 564.40 mF cm−2, which was two orders of magnitude higher than that of bare CNTs electrode (0.99 mF cm−2). Besides, the nanocomposites electrode also displayed a long circle life with only 3% capacitance decay after 1000 charge-discharge cycles indicating a promising electrode for supercapacitors.