HIGH-PERFORMANCE MWNT/MnO₂ SURPERCAPACITOR BASED ON CVD DIRECT GROWTH TECHNIQUE

In this work， multi-walled carbon nanotubes（MWNTs）are grown directly on nickel foam substrates without extra catalyst deposition by chemical vapor deposition（CVD）technique， followed by in situ deposition of manganese dioxide from the facile hydrothermal method to prepare the MnO₂-MWNT-Ni foam electrode for supercapacitor application. Due to superior structural and electronic conductivity properties， the MnO₂-MWNT-Ni foam electrode greatly improved the electrochemical reaction properties comparing with MnO₂-Ni Foam electrode， and the charge transfer resistance dropped from 0.411 Ω to 0.054 Ω. In the three-electrode system， the MnO₂-MWNT-Ni foam electrode presented a high specific capacitance of 771.5 F/g with capacitance retention of 102.7% after 1 000 cycles， demonstrated excellent capacitance performance and long-term stability. The MnO₂-MWNT-Ni foam composite exhibits superior properties of lowcost， high specific capacitance， high energy density & power density， and long-term cyclic stability， which is promising for supercapacitor and other battery applications.