High-Performance Electrochromic Devices Based on Poly[Ni(salen)]-Type Polymer Films

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Electrochromic materials are crucial for smart windows and displays.
• Poly[Ni(salen)]-type polymers offer potential as electrochromic materials.
• Developing stable and efficient electrochromic polymers is an ongoing research area.

Purpose of the Study:

• To investigate two novel poly[Ni(salen)]-type polymer films as electrochromic materials.
• To characterize their electrochemical and electrochromic properties.
• To evaluate their stability and performance in electrochromic devices.

Main Methods:

• Electrodeposition of poly[Ni(3-Mesalen)] (poly[1]) and poly[Ni(3-MesaltMe)] (poly[2]) onto ITO/PET substrates.
• Voltammetric characterization in different electrolyte solutions (LiClO4/CH3CN and LiClO4/propylene carbonate).
• Assessment of electrochromic properties including color changes, optical contrast, and electrochemical stability over redox cycles.
• Fabrication and testing of a solid-state electrochromic device using poly[1].

Main Results:

• Both poly[1] and poly[2] exhibited multielectrochromic behavior (yellow, green, russet).
• Poly[1] demonstrated superior electrochemical stability (9000 cycles) with good optical contrast (26.2%) and coloration efficiency (75.55 cm²/C).
• Poly[2] showed good optical contrast (58.5%) for green-to-russet transition but moderate stability.
• A solid-state device using poly[1] achieved high optical contrast (88.7%) and coloration efficiency (130.4 cm²/C).

Conclusions:

• Poly[Ni(salen)]-type polymer films are effective new electrochromic materials.
• Poly[1] exhibits excellent electrochemical stability and performance, suitable for practical electrochromic applications.
• The developed solid-state electrochromic device demonstrates significant potential for future technologies.