Preparation Of Manganese Dioxide And Its Performances As The Electrode Material Of Supercapacitor

The super capacitor is a new type of energy storage device and it is also a hot research in the field of new energy. But the super capacitor has a lower energy density,increasing the energy density of supercapacitor is the direction that researchers make efforts. The electrical conductivity of manganese dioxide ?MnO₂? is poor,but its resources are rich in nature, its cost is low, it is friendly to environment, its theoretical capacity is high and it has a wide electrochemical window. Therefore, it is widely used as supercapacitor electrode material.This article produces electrode materials of manganese dioxide by hydrothermal and improve the specific capacity of the manganese dioxide by doping carbon nanotubes. This article also produces manganese dioxide diatomite composite materials by hydrothermal method. We use SEM, XRD and other characterization methods, and electrochemical performance testing methods such as cyclic voltammetry, constant current charge and discharge and AC impedance to evaluate the electrochemical properties of the material. In this paper, the specific contents are as follows:?1?The structure morphology and electrochemical properties of MnO₂ were affected by temperature and time of hydrothermal reaction. This paper puts potassium permanganate and manganese sulfate as raw materials and controls the reaction time and temperature to produce different manganese dioxide electrode materials, and tests the surface morphology and electrical chemical properties of the manganese dioxide electrode materials at different reaction temperature and reaction time. The best surface morphology and electrochemical performance of the manganese dioxide electrode materials are seen in the reaction time 10h and temperature 140 ?, the discharge capacity is 241.03 F/ g.?2? The ratio of carbon nanotubes doped into MnO₂ has a great influence on their electrochemical properties of MnO₂. The MnO₂ composite electrodes that this article produces contain 5%, 10%, 20%, 40% and 60% of the carbon nanotubes. With the increase of carbon nanotube content, MnO₂ carbon nanotube electrode capacitance first increases and then decreases. When the carbon nanotube content is 20%, the composite electrode capacitance is maximum and the maximum is 352.15 F/g. The specific capacitance of the composite materials increase by 46% than specific capacitance of pure phase MnO₂ made under optimum conditions.?3? This paper puts potassium permanganate and manganese sulfate as raw materials, adds diatomite in the production process, controls the reaction temperature and the amount of diatomite to produce manganese dioxide electrode material load diatomite, and tests the surface morphology and electrochemical performance of electrode material diatomite load in the different reaction temperatures and different amount of manganese dioxide. The electrochemical performance of the electrode material is the best at a temperature of 140 ?. With the increase of diatomite content,manganese dioxide electrode capacitance load first increases and then decreases.When the diatomite content is 120 mg, the composite electrode capacitance is maximum and the maximum is 328.56 F/g. The specific capacitance of the composite materials increase by 36% than specific capacitance of pure phase MnO₂ made under optimum conditions.