Molten Salt Oxidation Synthesis Of SnO₂ Nanostructure And Its Application In Lithium Ion Battery

Nano-semiconductor materials have attracted extensive research interest because of their excellent properties that traditional bulk materials do not have.As wide band-gap transparent semiconductor material,tin dioxide nanostructures are widely investigated in lithium ion batteries,gas sensors,photocatalysis,solar cells and etc.The regulation of tin dioxide micromorphology and surface structure is the key to obtain excellent performance.Traditional preparation techniques including hydrothermal method and vapor deposition have many problems,such as time and energy consuming.In this paper,the scientific problems and key technologies in the preparation of tin dioxide with oxygen vacancies are studied.The main contents are as follows:(1)Flower-like tin dioxide nanostructures with oxygen vacancies were successfully prepared by molten salt oxidation method using anhydrous stannous chloride and natural graphite as precursors.The obtained flower-like tin dioxide nanostructures were characterized by X-ray diffraction,Scanning electron microscope,X-ray photoelectron spectroscopy and etc.,by which the existence of oxygen vacancy was confirmed,and the role of oxygen vacancy in providing carrier and improving conductivity of the product was also verified.At the same time,by combining thermodynamic calculation with experimental results,the formation mechanism of tin oxide nanostructures with oxygen vacancies was revealed.(2)Tin dioxide nanorods and few-layered graphite composite was synthesized by using anhydrous stannous chloride and natural graphite as reactants at 500℃ under optimized conditions,and was characterized by X-ray diffraction,Scanning electron microscope and Raman scattering.The obtained SnO2 nanorods and few-layered graphite composites were applied to the anode of lithium-ion batteries.After 500 cycles of charging and discharging cycles,high capacity of 495 mAh g-1 was obtained and was maintained.