Large coloration efficiency and fast response NiO electrochromic thin film electrode based on NiO nanocrystals

Nickel oxide (NiO) nanocrystals were fabricated by one-pot synthesis under the atmosphere of O 2 . Transmission Electron Microscope (TEM) test show that the average diameter was ca. 3 nm. X-Ray Diffraction (XRD) reveal the NiO nanocrystals were cubic structure. The as-prepared NiO nanocrystals were then surface-modified by pyridine to enhance their electrochromic (EC) performances. Measurement of EC properties of NiO nanocrystals was performed by testing NiO thin film electrode based on NiO nanocrystals in LiClO 4 /PC electrolyte with applied voltages of ±1.5 V, 50 s respectively. The results show that nanocrystals based NiO electrode have good EC performances. Optical modulation rate (ΔT) was 41.5% at the wavelength of 550 nm. Coloration switching time was 1.77 s and coloration efficiency (CE) was 114.7 cm 2 ·C −1 .