Application of Metal Alkoxoacetylacetonates in Preparation of Electrochromic Films Based on Nickel-Doped V2O5

Using vanadyl and nickel alkoxoacetylacetonates, films of vanadium pentoxide doped with 1, 3, and 10 mol % nickel oxide were obtained. All films crystallize in the tetragonal β-V₂O₅ modification. The materials are highly textured along axis (200) and consist of one-dimensional structures. However, at 3 and 10 mol % NiO, nanoparticles with sizes of 30–50 nm are also observed in addition to the one-dimensional structures. According to Raman spectroscopy data, the materials contain a significant amount of V⁴⁺ ions, but no traces of NiO phases were detected. From the standpoint of electrochromic properties, all obtained materials are cathodic, changing color to dark blue upon reduction and to a more transparent yellow upon oxidation. An increase in nickel content leads to a decrease in coloration efficiency and a slowdown of electrochromic processes. The results of the study indicate the potential of using nickel-doped V₂O₅-based materials obtained with metal alkoxoacetylacetonates as precursors for components in electrochromic devices.