Textile Based Electrochromic Cells Prepared with PEDOT: PSS and Gelled Electrolyte

Area of Science:

• Materials Science: Development of flexible hybrid textile-film electrochromic devices.
• Electrochemistry: Application of poly-3,4-ethylenedioxythiophene polystyrene sulfonate (PEDOT:PSS) for electrochromic displays.

Background:

• Flexible and bendable electrochromic devices are crucial for passive display applications.
• Spray coating technique was employed for fabricating hybrid textile-film devices on polyethylene polyethylene terephthalate (PEPES) membranes.

Discussion:

• The electrolyte comprised a gelatin glycerol mixture with calcium chloride, and titanium dioxide served as an ion storage layer.
• A carbon-based dispersion was utilized for the counter electrode on a polyester rip-stop fabric, achieving a PEDOT:PSS sheet resistance of 500 Ohm/sq.
• The device demonstrated individually addressable pixels in a 5x5 matrix, with an initial switching time of 2 seconds at 2.0 V.

Key Insights:

• Titanium dioxide enhanced the contrast of the electrochromic layer, but coloration was not self-sustaining, requiring a minimum of 0.5 V.
• Switching time increased to approximately 4 seconds at 2.8 V after 12 months, indicating performance degradation.
• Glycerol in the electrolyte extended the device lifetime by retaining moisture, facilitating charge carrier transport.

Outlook:

• Further research can focus on improving the long-term stability and self-sustaining coloration of these flexible electrochromic devices.
• Optimization of electrolyte composition and electrode materials could lead to enhanced performance and durability.
• Potential applications include wearable electronics, smart textiles, and low-power displays.