Electrochromic and energy storage properties of amorphous TiO2 film prepared by pulsed magnetron sputtering

In this study, amorphous TiO 2 nanofilm has been prepared by a pulsed magnetron sputtering method. The uniform amorphous TiO 2 nanostructure shows the excellent electrochromic performance in visible and near-infrared bands, including the wide transmittance modulations of 63.4 % at 460 nm and 22.1 % at 2000 nm, the short switching time of 9.4 s/8.6 s for coloring/bleaching, and the large coloration efficiency of 62.4 cm 2 /C at 460 nm. Furthermore, the amorphous TiO 2 nanofilm has the feasible energy storage property. The TiO 2 film exhibits a large areal capacitance with good rate performance (9.3 mF/cm 2 ). It provides an intuitive method for monitoring energy storage through changes in TiO 2 electrode color. In addition, the oxygen concentration and sputtered time have significant effects on the microstructure, crystallization and electrochemical properties of TiO 2 films. These results have significant guiding significance for the development of amorphous TiO 2 films and related advanced dual functional devices with electrochromism and energy storage.