Controlled Synthesis and Application Exploration of Titanium Oxide and Its Carbon Composite Nanomaterials
|School||Beijing University of Chemical Technology|
|Keywords||Titanium dioxide Titanium oxy compounds Micro- nano composite materials Lithium-ion battery anode material|
This thesis around titanium oxides and their work with the control the synthesis and properties of carbon composite materials design and synthesis of TiO2 nano- rods with carbon of the sea urchin -like self-assembly of micro-nano composite titanate nanocrystals , etc. and TiO2-C micro - nano composite materials in the performance of the lithium-ion battery electrode materials with initial exploration , the inherent relationship between the preliminary interpretation of the structure and properties . By solvothermal method using titanium tetrachloride hydrolysis , glucose dehydration carbonation and esterification reaction step synthesis of a novel TiO2 nano- rods and carbon self-assembly of micro-nano composite materials , and designed a series of comparative experimental system to study a variety of synthetic conditions , such as the type of titanium source , the concentration , the kind of alcohol , the reaction temperature and time , the filling degree , the amount of glucose- , heat treatment temperature and the seed crystal is the impact on the morphology and structure . Furthermore, by controlling the synthesis conditions to obtain a TiO2 @ C nanoparticles . Testing means of SEM, TEM, Raman, XRD showed that the novel TiO2-C composite material is 10-20 nm of TiO2 nano-rods closely arranged and pointing to the center of the sphere , and wherein the carbon uniformly dispersed structure of sea urchin - like assembly , the diameter of about 500 nm -10μm. The electrochemical tests showed that the composite material has a better than the capacity and cycle characteristics . 600 ℃ deal with a carbon content of 20 wt% samples cycle of charge and discharge current of 30 mA · g-1 in the 1-3 V TiO2 initial discharge capacity of 335mAh · g-1, a TiO2 0.78 Li can be reversibly embedded . 700 ℃ deal with a carbon content of 1.7 wt% sample current of 20 mA · g-1 in the first discharge capacity of 0.1-3V test 263.7mAh · g-1, remains 244.6mAh · g - 1 cycle 70 times . Titanate nanocrystals synthesized using a hydrothermal and solvothermal method . By controlling the alkalinity , the kind of solvent and the volume , TiO2 added in an amount , and other conditions to achieve the control of the morphology and structure of the titanate , and synthesized having the desired crystal structure of titanate nanosheet and nanotubes . The results confirmed that the alkalinity of the most important factors affects the morphology and structure , the addition of the low boiling organic solvent is conducive to the formation of nanotubes . Through the exchange of lithium-ion and lithium hydroxide , further synthesized rock salt type LiTiO2 nanosheets its associated performance needs further study .