Reversible Zn2+ Insertion in Tungsten Ion-Activated Titanium Dioxide Nanocrystals for Electrochromic Windows

Zinc-anode-based electrochromic devices (ZECDs) are emerging as the next-generation energy-efficient transparent electronics. We report anatase W-doped TiO2 nanocrystals (NCs) as a Zn2+ active electrochromic material. It demonstrates that the W doping in TiO2 highly reduces the Zn2+ intercalation energy, thus triggering the electrochromism. The prototype ZECDs based on W-doped TiO2 NCs deliver a high optical modulation (66% at 550 nm), fast spectral response times (9/2.7 s at 550 nm for coloration/bleaching), and good electrochemical stability (8.2% optical modulation loss after 1000 cycles).

Automated summary

This study reports W-doped anatase TiO2 nanocrystals as an active electrochromic material for Zn2+ in zinc-anode-based electrochromic devices. The doping of W in TiO2 significantly reduces the intercalation energy of Zn2+, leading to electrochromism. Prototype ZECDs based on W-doped TiO2 NCs exhibit high optical modulation, fast spectral response times, and good electrochemical stability.