Self-healing electrochromic energy storage devices based on PEDOT:PSS

Abstract

Poly (3,4-ethylenedioxythiophene): poly (4-styrenesulfonic acid) (PEDOT:PSS) is a kind of widely used polymer with excellent electrical conductivity. In this study, PEDOT:PSS was modified to achieve self-healing ability while maintaining excellent energy storage properties. The modified PEDOT:PSS hybrid film demonstrated instantaneous self-healing ability due to physical cross-linking after being subjected to different external cuts (the average self-healing time was 1.44 s). When pressed at different rates, the film had a self-healing time of less than 0.12 s, and a retention rate of 74% after pressing 1750 times consecutively at a rate of 8.6 cm s⁻¹. The mechanism of self-healing was investigated using theoretical calculations. Tungsten trioxide (WO₃) was further introduced into the PEDOT:PSS hybrid film to fabricate electrochromic energy storage devices (EESDs), achieving a specific capacitance of 105.35 mF cm⁻² and a capacitance retention of 98.2% after 1000 cycles. In the organic/inorganic hybrid system, the modified PEDOT:PSS film acted as both a protective coating for WO₃ and exhibited a synergistic color change with WO₃, ultimately improving the overall performance of the device. The present self-healing strategy can help design restorers for EESDs and can be extended to other new rechargeable electrochromic battery systems with good application prospects.