Foil-based TiO2/gel electrolyte/Ni1-xO electrochromic device made of electrochromic pigment coatings

Thin electrochromic coatings were obtained by co-grinding the mTiA particle aggregates (300 nm in size) with open-corner heptaisobutyl trisilanol POSS (T(8) IB(7)(OH)(3) POSS) acting as dispersant. After the addition of titanium tetraisopropoxide (3-5%) the mTiA pigment dispersion was deposited on FTO glass and plastic ITO PET foils and coatings were obtained by thermal treatment at 150 °C. Optical transmittance and luminous haze from 2 to 6% of the coatings were determined from the corresponding UV-Vis spectra. The achieved electrochromic effect was evaluated by electrochemical charging/discharging in 1 M LiClO(4)/PC electrolyte. Results revealed that the colouring/bleaching changes depended on the extent of grinding and the size of the milling zirconia beads, enabling to distinguish between the surface charging of the mTiA grains and the filling and emptying of the anatase density of states. mTiA pigment coatings deposited on plastic foil were used in combination with Ni(1-x)O pigment coatings for construction of foil-based electrochromic device employing novel gel electrolyte with ionic liquid co-solvent.