Enhanced Coloration Time of Electrochromic Device Using Integrated WO₃@PEO Electrodes for Wearable Devices.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Electrochromic technologies are gaining traction for low-power displays.
• Tungsten trioxide (WO3) is a stable electrochromic material but suffers from slow coloration in solid films due to limited surface area and ion diffusion.
• Demand for faster, paper-like displays necessitates improved electrochromic device performance.

Purpose of the Study:

• To fabricate a fibrous WO3@poly(ethylene oxide) (PEO) composite structure for faster electrochromic responses.
• To enhance lithium-ion (Li-ion) transport and coloration speed in electrochromic devices.
• To develop a flexible electrochromic device suitable for fabric applications.

Main Methods:

• Fabrication of WO3@PEO composite nanofibers using electrospinning.
• Characterization of the fibrous structure's morphology and electrochromic properties.
• Fabrication of a flexible electrochromic device on a conductive knitted fabric substrate using gel electrolytes.

Main Results:

• The WO3@PEO fibrous structure exhibited a significantly reduced Li-ion diffusion path, leading to faster coloration times.
• The optimized composite showed a high coloration efficiency of 61.3 cm²/C and a rapid 1.6s coloration time.
• A functional electrochromic device was successfully demonstrated on fabric, displaying color changes via voltage modulation (-2.5 V to 1.5 V).

Conclusions:

• Electrospinning a WO3@PEO fibrous structure is an effective strategy to overcome the limitations of solid WO3 films for electrochromic applications.
• The PEO component enhances ionic conductivity, facilitating rapid Li-ion transport and improving electrochromic device speed and efficiency.
• The developed flexible electrochromic device on fabric shows promise for wearable electronics and novel display technologies.