posted on 2022-01-26, 22:29authored byCong Wu, Zewei Shao, Wenbo Zhai, Xinshui Zhang, Chang Zhang, Chengyu Zhu, Yi Yu, Wei Liu
There
is a keen interest in the use of electrochromic materials
because they can regulate light and heat, thereby reducing the cooling
and heating energy. However, the long response time, short cycle life,
and high power consumption of an electrochromic film hinder its development.
Here, we report an electrochromic material of complex niobium tungsten
oxides. The Nb18W16O93 thin films
in the voltage range of 0 to −1.5 V show good redox kinetics
with the coloration time of 4.7 s and bleaching time of 4.0 s, respectively.
The electrochromic device based on the Nb18W16O93 thin film has an optical modulation of 53.1% at a
wavelength of 633 nm, with the coloration efficiency of ∼46.57
cm2 C–1. An excellent electrochemical
stability of 78.1% retention after 8000 cycles is also achieved. These
good performances are due to the fast and stable Li-ion intercalation/extraction
in the open framework of Nb18W16O93 with multiple ion positions. Our work provides a strategy for electrochromic
materials with fast response time and good cycle stability.