A Quasi-Solid-State Tristate Reversible Electrochemical Mirror Device with Enhanced Stability

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Conventional electrochromic smart windows face challenges in durability, switching speed, optical states, and cost, hindering widespread adoption.
• Reversible electrochemical mirror (REM) devices offer tunable optical states but require further development for practical applications.

Purpose of the Study:

• To develop a novel REM electrochromic device utilizing a CuSn alloy for enhanced performance.
• To investigate the electrochemical tunability, durability, and optical properties of the CuSn-based REM device.

Main Methods:

• Fabrication of a REM electrochromic device incorporating a CuSn alloy.
• Electrochemical cycling to assess switching reversibility between transparent, greyish-blue, and mirror states.
• Evaluation of cycling stability, resistance to oxidation, and near-infrared (NIR) reflectance properties.

Main Results:

• The CuSn-based REM device demonstrated superior cycling stability with 2400 cycles in transmittance mode and 1000 cycles in reflectance mode.
• The CuSn alloy film exhibited excellent resistance to ambient air oxidation and superior NIR reflectance, with significant thermal modulation.
• The device maintained its mirror state for over 100 minutes with zero power consumption.

Conclusions:

• The developed CuSn-based REM electrochromic device offers a promising solution for energy-efficient smart windows due to its high durability and tunable optical properties.
• The use of Sn as an electrochemical mediator in the CuSn alloy facilitates efficient electrodeposition and dissolution, enhancing device performance.
• The REM device's ability to maintain optical states with zero power consumption makes it a strong candidate for energy-saving applications.