Preparation And Properties Of The Composite Capacitance Material Based On Manganese Dioxide And Carbon-based Materials

Super capacitor is a device to store electrical energy in recent years of extensive research, their research is focused on selection and production of the electrode material. Carbon nano-materials, active metallic oxides, with excellent electrical conductivity of polymers and composites formed from them is an important raw material of high-performance electrode of the capacitor. Currently the focus of research is preparing high-performance composite electrode material, this paper prepared three-dimensional self-supporting carbon nanotube/carbon fiber composite structure with manganese dioxide heterostructure to form a composite material, and the composite materials for self-supporting electrode material of the supercapacitor, through experimental tests found that the electrode material having excellent capacitance effect. In addition, the symmetric supercapacitor is assembled with electrode material. by experimental tests found that the symmetrical capacitor has good flexibility and stability.In this paper, using electrospinning technology obtained polyacrylonitrile nanofibers doped with acetylacetone iron, then the resulting nanofibers carbonize to form carbon fiber. Finally, carbon fiber as base, acetylacetone iron as a catalyst at a reaction temperature of 800℃, using CVD method to obtain self-supporting CNTs/CNF. The prepared carbon fiber/carbon nanotube has high electrical conductivity(1250 S/cm), significant specific surface area and awesome flexibility. The reaction of 0.5h CNTs/CNF in neutral solution of potassium permanganate and get CNTs/CNF/MnO2, by calculating the CNTs/CNF/MnO2 composite electrode material show a high specific capacitance of 517 Fg-1 at a scan rate of 5 mVs-1. additional use GCD method to test capacitance remains the 75% of initial value at cycle number of 1000, which showed brilliant capacitance repeatability. By comparing the experimental data and testing can be found the electrochemical properties of carbon nanotube/carbon fiber/manganese oxide composite electrode material with the same quality active material is far superior to carbon fiber/manganese oxide composite electrodes. Finally, high-performance symmetric capacitor is made up of two CNTs/CNF/MnO2 composite electrode material, the symmetrical high-performance capacitor show power density of 7000 W/kg, the energy density reaches a maximum 3.88 Wh/kg. The supercapacitor is bent 100 times and its capacitance remains the 70% of initial value.By comparing the experimental data we can find such a designed heterostructure can enhance the electrochemical properties of the electrode material, at the same time also believe that such a self-supporting CNTs/CNF/MnO2 heterogeneous composite materials have great development potential in flexible high-performance capacitor.