Three-Dimensional (3D) Nanocomposites of MnO2-Modified Mesoporous Carbon Filled with Carbon Spheres/Carbon Blacks for Supercapacitors

Herein, three-dimensional (3D) nanocomposites of diverse carbon materials, (e.g., mesoporous carbon (MC) filled with carbon spheres (CS) and carbon blacks (CB)) and MnO2 were synthesized and explored for high-performance supercapacitors. By tuning the amount of KMnO4 the morphology and pore structure of MC-CS-MnO2 and MC-CB-MnO2 nanocomposites could be controlled. A series of electrochemical measurements were performed, exhibiting higher specific capacitance and stable cycling performance of the 3D nanocomposites. Meanwhile, MC-CS-MnO2 demonstrated the larger specific capacitance of 326 F g-1 and interestingly an increase specific capacitance for MC-CB-MnO2 was found after 1000 cycles. In principle, these findings show great potential in developing long cycling and electrochemically stable supercapacitors.