Low-Heat-Driven Self-Healing Flexible Electrochromic Film Relying on a PEDOT:PSS-Based All-Organic Composite

Electronic materials capable of bionic self-healing have received extensive attention in view of the urgent need of extending device life, maintaining operation safety, and reducing renewal costs. Among them, conducting polymers (CPs), especially poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), have become a research hotspot due to their intrinsic and tunable electrical conductivity, macromolecule nature with good processability, good stability, combination ability, etc. Herein, an all-organic PEDOT:PSS/poly(ethylene glycol)/2-amino-4-hydroxy-6-methylpyrimidine-encapsulated polyurethane film with high electrical conductivity, remarkable self-healing ability, excellent mechanical flexibility, and strong water resistance is created by the ingenious design of a multiple hydrogen-bonding strategy. Moreover, the film was fabricated easily from a solvent (water/methanol)-processable dispersion with fast drying and “green” advantages. The film crack can be healed by relatively low-temperature heating at 65 °C for 5 min with recovered smooth surface and electrochromic properties, including high optical contrast (ΔT) values of up to 68.2%, fast oxidation and reduction responses (0.24 and 0.49 s, respectively), and excellent coloration efficiency (246.4 cm2 C–1). The flexible electrochromic device employing this film as an active layer still maintained an ΔT value of more than 47% and can remain above 90% even after 1000 times of operation or mechanical bending. This research will greatly enhance the reliability of PEDOT:PSS-based organic film electronic devices.