Starburst macromonomers with carbazole arms: From electropolymerization to electrochromic prototypes with energy storage capability

This study follows three directions in developing smart materials with electrochromic and energy storage functions: effective macromolecular blueprint, viable electropolymerization processing, and the design-prototype pathway. A fully conjugated macromonomer with an aryl focal point and three carbazole branches was used as the main core for two dendrimer-like macromonomers with amide-linked carbazole or triphenylamine arms. Their electropolymerization rendered defect-free polymeric films with a granular surface. Systematic connections between structural variations and the optical, electronic, morphological, and electrochemical conduct were established. The electrochromic activity and stability, coloration efficiency, charge-discharge patterns, specific areal capacitance, and electron-transfer processes highly depend on external building blocks, conjugation type, and films' topography and topology. A laboratory-scale prototype using the most balanced polymer showed reliable electrochromic performance: 0.41 s for coloration, 3.82 s for bleaching, 31.33% maximum optical contrast, 125 cm 2 C −1 coloring efficiency, and 25% efficiency decay after 100 cycles. The same prototype acted as a hybrid-type pseudocapacitor and delivered convincing energy storage outcome: 0.62 mF cm −2 (GCD, 10 μA cm −2 , relatively stable at higher current density) areal capacitance, 98.2% Coulombic efficiency, 1453 μW cm −2 power density, 542 μWh cm −2 energy density, 7.14% capacitance decay after 500 cycles, and a 0.34 S cm −1 conductivity.