Tungsten trioxide nano powder may be used to prepare a WO3 electrochromic film, and then be used to prepare an all-solid-state electrochromic glass. Such smart glass is mainly applied to buildings or automobiles for heat insulation, energy reduction and environmental protection. Some experts used the sol-gel method to prepare WO3 electrochromic thin films by using tungsten powder and H2O2 as the main raw materials, and doping them with polyethylene glycol and propylene carbonate, and assembled such film into electrochromic glass devices.

Tungsten trioxide nanopowder may be prepared into a WO3 electrochromic film, and then be used to prepare an all-solid electrochromic glass - a smart glass, which is often applied in the field of building for achieving the performance of high thermal insulation, high heat preservation and high transparency. This is because nano particle size tungsten trioxide has excellent electrochromic properties as well as electrochemical stability. Therefore, WO3 has become one of the most studied electrochromic materials.

Tungsten trioxide nanopowder is an important raw material for the preparation of a smart window. The prepared all-solid smart window is often applied in smart buildings to play the role of heat insulation, energy conservation and consumption reduction. Experts have prepared smart heat insulating windows with better electrochromic reversibility and optical adjustment characteristics, which are structured with V2O5/solid lithium ion conductor/WO3.

Nano tungsten oxide may be used to prepare an electrochromic film, which may be used to produce a high-performance electrochromic glass, that is, an environmentally-friendly smart glass with heat insulating performance. According to experts, a complete electrochromic glass assembly consists of five layers: ITO conductive glass layer, electrochromic layer, ion conductor layer, complementary electrochromic layer, ITO conductive glass layer. The three layer film in the middle is the core material.