Continuous Solar Energy Conversion Windows Integrating Zinc Anode-Based Electrochromic Device and IoT System.

Area of Science:

• Materials Science
• Renewable Energy
• Smart Buildings

Background:

• Solar cells and electrochromic windows are key for green buildings.
• Solar-charging zinc anode-based electrochromic devices (ZECDs) can address solar intermittency but suffer from limited storage capacity.
• This limitation leads to wasted solar energy and overcharging issues.

Purpose of the Study:

• To develop spectral-selective dual-band ZECDs for continuous solar energy transport to indoor appliances.
• To enable remote control of electrochromic devices for repeated bleached-tinted cycles during daytime.
• To enhance energy management in green buildings by overcoming ZECD limitations.

Main Methods:

• Utilized hexagonal phase cesium-doped tungsten bronze (h-Cs0.32WO3, CWO) nanocrystals for dual-band ZECDs.
• Investigated independent control of near-infrared (NIR) and visible (VIS) light transmittance.
• Assessed cycling stability and thermal insulation properties of the CWO//Zn//CWO prototype device.

Main Results:

• Achieved significant transmittance modulation for NIR and VIS light (∆T = 73.0% at 700 nm, ∆T = 83.7% at 1200 nm).
• Demonstrated excellent cycling stability with only 0.8% optical contrast decay at 1200 nm after 10,000 cycles.
• The CWO//Zn//CWO device exhibited remarkable thermal insulation, with a 10 °C difference between bright and dark modes.

Conclusions:

• Developed spectral-selective dual-band ZECDs with superior optical and stability performance.
• Created an Internet of Things (IoT) controller for wireless, remote management of the CWO//Zn//CWO window.
• This technology holds substantial potential for future impact on green buildings through efficient solar energy utilization and control.