Multi-color electrochromic film, device and preparation method of multi-color electrochromic film

The invention relates to the field of electrochromism, in particular to a multi-color electrochromism film, a device and a preparation method of the multi-color electrochromism film. The invention develops a photochemical method for preparing the colorful electrochromic film with the spherical porous structure, and meanwhile, the crystallinity of the film can be regulated and controlled by regulating the annealing temperature in the later period. Wherein in the electrochromic process of the amorphous film, the contribution degree generated by the surface pseudocapacitance effect is far greater than the contribution degree of traditional ion deintercalation, so that the film is relatively high in transmittance and wide in optical modulation range, can show multiple colors of yellow, blue, green and brown in the process of applying positive voltage to negative voltage, and is high in color changing speed; the cycling stability is high; the electrochromic device assembled by the thin film prepared by the inventi