Solid Polymer Electrolytes Based on Gellan Gum and Ionic Liquid for Sustainable Electrochromic Devices

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Materials sustainability is crucial for technological advancement.
• Environmentally friendly electrolytes are needed for energy devices.
• Ionic liquids offer unique properties for electrolyte applications.

Purpose of the Study:

• To prepare and characterize novel solid polymer electrolytes (SPEs) based on gellan gum and ionic liquid (IL).
• To investigate the application of these SPEs in electrochromic devices (ECDs).
• To develop sustainable and high-performance electrolytes for flexible ECDs.

Main Methods:

• Gellan gum and varying concentrations of 1-ethyl-3-methyl-imidazolium-thiocyanate [Emim][SCN] ionic liquid were used to prepare SPEs.
• Morphological, structural, thermal, and mechanical properties of SPEs were analyzed.
• Ionic conductivity was measured at different temperatures.
• ECDs were fabricated using PEDOT:PSS and tested for electrochromic performance.

Main Results:

• SPEs exhibited compact morphology, uniform surface, and good IL distribution without affecting gellan gum crystallinity.
• Developed SPEs showed thermal stability up to ~100 °C and suitable mechanical properties.
• The highest ionic conductivity achieved was 6.0 × 10^-3 S cm^-1 at 30 °C and 1.8 × 10^-2 S cm^-1 at 90 °C (39 wt% IL).
• A flexible ECD was successfully demonstrated, operating below 1.0 V.

Conclusions:

• Gellan gum-based SPEs with ionic liquids are promising for sustainable materials.
• The developed SPEs offer excellent ionic conductivity and thermal stability for ECDs.
• This research paves the way for high-performance, eco-friendly electrochromic devices.