| The global energy crisis caused by excessive consumption of fossil fuels(coal, oil and natural gas), making humans more and more aware of the importance of the new energy development and utilization. Supercapacitor is a new type of energy storage device with high power density, good reversibility, wide working temperature and long cycle life and many other advantages that arouse the researchers’ attention. The research on electrode material is important because the electrode material is the main factor that affects the electrochemical performance of the supercapacitors. Metal oxides have excellent reversibility, high energy density and specific capacitance, which are widely used as electrode materials for supercapacitors. Two or more than two kinds of metal oxides make up of composite materials due to the synergistic effect usually have more great performance than the single metal oxide and research about this field is with great focus. In this paper, we analyze the morphology, crystal structure and pore structure of the active substance through transmission electron microscopy, X-ray diffraction,focused ion beam scanning electron microscope and specific surface area tester. And the electrochemical properties of the samples were studied by cyclic voltammetry,galvanostatic charge-discharge and electrochemical impedance spectroscopy method.Firstly, we prepare antimony doped tin oxide nanoparticles by hydrothermal method, and then prepare ATO/MnO2 nanocomposites which makes the ATO nanoparticles embedded in MnO2 nanosheets which forming coating structure. Using the excellent conductivity of ATO to improve the use of MnO2 in the charge and discharge process is one of the main ideas of the paper. By adjusting the amount of antimony in ATO and getting the optimal ratio of the maximum electrochemical properties. The results show that 7.5 percent antimony doped(molar ratio [Sb]/[Sn] is7.5:100) having a maximum specific capacitance(186.8 F/g), while single ATO and commercial MnO2 are 1.4 F/g and 14.5 F/g respectively. The higher specific capacitance and excellent cycle stability show that ATO/MnO2 nanocomposites are wonderful materials as supercapacitors electrode.Then the dandelion-like CuO hollow spheres are prepared by using TOAB as surfactant, then loading MnO2 on CuO spheres. When reaction time is two hours, the surface of CuO spheres are coating with MnO2 nanoparticles. As time goes on to six hours, nanoparticles change to nanoflakes and turn to nanoflowers until twenty-fourhours. We analyze the chemical composition, crystal structure and morphology of dandelion-like CuO hollow sphere and CuO/MnO2 core-shell structure by using XRD,SEM testing methods, and speculate the formation mechanism. In a three electrode system, CuO/MnO2 core-shell structures have a higher specific capacitance(228 F/g)than pure dandelion-like CuO hollow structures(10 F/g) which increase to 20 times. At the current density of 0.6 A/g, there is a reservation of 82.2% of original specific capacitance after 5000 cycles which exhibits a splendid application prospect.Composite materials are usually more outstanding than single materials due to synergistic effect. In this article, guided by this idea we compound the ATO/MnO2 and CuO/MnO2 nanocomposites materials which provide a reliable way for further research and development of novel micro structure of composite materials. At the same time, the nanocomposites materials prepared show preeminent electrochemical performance which can use as the electrode material of supercapacitors. |
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