The invention discloses an electrochromic film adopting an amorphous / crystalline
tungsten trioxide core-shell structure and a preparation method of the film. The method comprises steps as follows: white
tungstic acid is dissolved in a
hydrogen peroxide solution, the mixture is applied to a conductive surface of a conductive substrate, and a conductive substrate covered with a
crystal seed layer is obtained; a
tungsten source is dissolved in water, the pH value is adjusted,
ammonium sulfate is added, a precursor solution is formed, a reaction is conducted in the precursor solution at the temperature of 150-250 DEG C for 4-10 h, and a
tungsten trioxide nanowire array film is obtained. The tungsten source is dissolved in the water, the
hydrogen peroxide is dropwise added, the pH value is adjusted, an electrodeposition solution is formed, and the film can be obtained through electrodeposition of amorphous
tungsten oxide with a
constant voltage method. The film prepared with the preparation method has the
nanowire core-shell
coating morphology, is good in electric
connectivity and has the advantages of large spectrum adjusting range, high coloration efficiency and long cycle life, meanwhile, the preparation technology is convenient to control, the production cost is lower, massive production can be realized, and industrialization is easy to realize.