ProDOT-containing polyamides: On the road from energy storage materials to perspective electrochromic capacitive windows

Pursuing to develop novel polymer-based electrode materials and explore their performance in electrochromic capacitive windows (ECWs), three polyamides containing propylenedioxythiophene (ProDOT) units were synthesized. The polymers were processed into thin coatings and subjected to rigorous structural and photophysical characterization, with focus on the electrochromic response and energy storage capability. One of the polymers showed electrochromic response with ultrafast color change (0.8 s for coloring) from highly transmissive yellow to deep green, opposite to most ProDOT-based materials that exhibit bleaching trends during oxidation, which is more convenient for smart glazing. A coloration efficiency of 358 cm 2 x C -1 , a maximum CE decay of 2.6 % after 100 cycles, and an excellent electrochromic stability, even up to 500 cycles was achieved for this material. In three-electrode cell configuration, this polymer revealed practical energy storage properties, including a wide voltage window, a good capacitance, of 5.63 mF x cm -2 , and an outstanding electrochemical cycling durability. Therefore, a prototype polyamide based-ECW device was built and its overall performance was explored. Due to the well capability of this polymer to simultaneously operate as a smart color changing and energy storage electrode, it can be considered as promising material for use in energy storage smart windows with potential applications in green-enabling technologies.