Tunable Capacitive Behavior in Metallopolymer-based Electrochromic Thin Film Supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Volumetric capacitance is crucial for energy storage in lightweight and microelectronic devices.
• Existing energy storage solutions often face limitations in achieving high volumetric performance.
• Metallopolymers offer potential for advanced electrode materials due to their tunable properties.

Purpose of the Study:

• To develop novel electrochromic metallopolymer-based electrode materials for high volumetric capacitance.
• To investigate the relationship between metallopolymer structure, electrical conductivity, and supercapacitor performance.
• To evaluate the potential of these materials for compact microenergy storage systems.

Main Methods:

• Synthesis of three distinct Fe(II)-based metallopolymers with varying ligand structures.
• Fabrication of symmetric two-electrode supercapacitor devices using the synthesized metallopolymers.
• Electrochemical characterization including cyclic voltammetry, galvanostatic charge-discharge, and long-term cycling stability tests.

Main Results:

• Achieved high volumetric capacitance up to 866.2 F cm⁻³ at 0.25 A g⁻¹.
• Demonstrated superior performance in poly-Fe-L2 (544.6 F cm⁻³, 75.5 mWh cm⁻³ at 1 A g⁻¹), correlating with higher electrical conductivity.
• Exhibited excellent operational stability under continuous cycling, indicating material durability.

Conclusions:

• Ligand structure variation is key to tuning electrical conductivity and achieving high volumetric performance in Fe-based metallopolymers.
• These metallopolymers represent promising candidates for high-performance, compact microenergy storage systems.
• The tunable electro-optical and electrochromic properties open avenues for integrated smart functionalities in wearable electronics.