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The electrochemical capacitor having higher energy density than conventional electrostatic container, the ratio of the power density and cycle life of the secondary battery is higher, the new type of energy storage device is a comprehensive performance in between. The electrochemical capacitor current charge and discharge, long cycle life, wide temperature range makes its research in recent years showing unprecedented boom. The electrode material is the key to determining the performance of electrochemical capacitors, this paper selected the electrochemical performance is good, cheap and environmentally friendly manganese dioxide as electrode material, the use of a variety of materials characterization and electrochemical analysis by means of a high load of thick electrode (10 mg/cm2, 100μm) under the conditions of material morphology, electrolyte type and concentration on the capacitor performance, electrode preparation, different the manganese carbon composite materials capacitance characteristics. The main content and innovations are as follows: 1. Room temperature liquid phase catalytic method, wet chemical method, low temperature hydrothermal method were prepared core-shell, sea urchins, nanosheets reunion microspheres, four different morphologies of nanorods reunion microspheres micro nanometer manganese dioxide material, and by XRD, SEM, N2 adsorption-desorption, cyclic voltammetry, galvanostatic charge-discharge means of AC impedance test microstructure morphology and electrochemical properties. The results showed that the degree of crystallinity, specific surface area synthesized dioxide manganese material performance capacitance capacitor performance, but the morphology of the microstructure of the material has a more important impact. Close the mesoporous structure of the network type is better than loose open structure having capacitive properties, pore size of about 8 m high ratio of pore volume of synthetic manganese dioxide material, it is advantageous to produce a high electric capacity in a neutral electrolyte Na2SO4 . Nanorods reunion the microsphere material has good electrochemical activity and cycle performance, the first discharge capacity of about 88 F / g, 50 mV / s scan rate higher than the capacity after 2000 cycles voltammetry to 114.2 F / g for the initial discharge capacity of 130%. Investigated nanorods aggregates microsphere material synthesis, the electrode preparation of process parameters on the micro-structure and electrochemical properties of the material morphology. The results showed that the material synthesis temperature of 70 ° C, and a synthesis time of 30 min, stirring speed 100r/min, the electrode drying temperature of 70 ° C, the pressure to 6 Mpa prepared capacitor electrode has a relatively good performance. Using a magnetic stirrer mixing manganese dioxide - carbon composite electrode capacitance performance good. By XRD, SEM, TEM, cyclic voltammetry, galvanostatic charge-discharge and AC impedance test means to carry out the investigation and analysis of material composition, morphology and performance. The results showed that the diameter of about 20 nm carbon nanotubes as carbon and manganese carbon ratio of 8:2, the composite electrode has the best electrochemical performance. In the high discharge current density of 1 A / g power density 400W/kg, the composite electrode discharge capacity to 127.5 F / g, the energy density of 11.3 Wh / kg, respectively, 61.8% higher than that of pure manganese oxide electrode , 61.4%.
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