| Electrochromic glass has been widely used in smart-windows, large-area information displays, rear-view mirrors for automobiles and information storage etc. Tungsten oxide （WO3） has been the most widely and deeply studied inorganic electrochromic materials for its excellent coloration efficiency and good reversibility, but it still has poor contrast and long response time. A better way to solve this problem is either to fabricate nanoporous materials or to dope WO3. In this thesis, lithium titanate nanotubes （Li-TNTs） used as the supporter which can provide convenient channels for Li ion as well as deepen its insert depth.The titanium nanotubes （TiO2-NTs） and sodium titanate nanotubes （Na-TNTs） were fabricated by hydrothermal method, and Li-TNTs was obtained by ion-exchange. TEM and XRD results showed that Li-TNTs has a inner and outer diameter of 5 and 8 nm, and its interlayer spacing was 0.83 nm. It has larger specific surface area for its larger inner diameter and narrower interlayer spacing compared with Na-TNTs. The WO3 was fabricated onto TiO2-NTs and Li-TNTs by wet-immersion. Elemental analysis results showed that W/Ti ratio was 1/2, the WO3 particle was found on the outside of nanotubes and has a uniform size of 10 nm. WO3, WO3/TiO2-NTs and WO3/Li-TNTs thin films with 300 nm thickness were fabricated onto ITO glass by spin coating.Some electrochromic properties of WO3, WO3/TiO2-NTs and WO3/Li-TNTs thin films were detected. It found that WO3/Li-TNTs thin film has a faster lithium diffusion coefficient （6.1×10-10 cm2/s）, larger transmittance contrast （74.1%） and faster color switching time （0.4/0.15 s） as well as cycling stability. The electrochromic properties of WO3/Li-TNTs thin film with various W contents have also been studied. The results showed that WO3/Li-TNTs with W/Ti ratio of 1/2 has optimal lithium diffusion coefficient and color modulation. A lower W/Ti ratio may lead to insufficient materials response and a higher ratio may hinder the ion diffusion.LiClO4/PC liquid electrolyte has good ionic conductivity, but it can only used in laboratory because it is easy to generate bubbles and leakage. In this thesis, the ET-PC/EC-PMMA-LiClO4 gel electrolyte was prepared, and the effects of PMMA contents and LiClO4 concentration on the electrolyte conductivity were studied. The results showed that electrolyte has optimal viscosity and conductivity to fabricate a electrochromic device with PMMA contents of 20-25% and LiClO4 concentration of 1 mol/L. |
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