Design of cost-effective multi-colored nanoporous 3D conjugated polymer for stable flexible electrochromic supercapacitors

Flexible electrochromic-supercapacitors (FESs) have emerged as competitive candidates in diverse fields like sustainable energy storage and flexible electronics. The development of low-cost, efficient, active, and stable electrochromic-supercapacitor electrode materials is still challenging for high-performance FESs. Herein, we propose a nanoporous 3D conjugated polymer network design strategy to achieve a cost-effective yet high-performance electrochromic-supercapacitor from triphenylamine (TPA) and 3,4-ethylenedioxythiophene (EDOT). The nanoporous 3D conjugated polymer network of TPA and EDOT is realized by efficiently synthesizing a conjugated tripod-structure TPA-EDOT precursor and its successive low-potential electropolymerization . The resulting 3D nanoporous polymer ( PTEPA ) has stable reversibility (91.1% retention after 6000 doping-dedoping cycles), good specific capacitance (137 F g −1 , 1 A g −1 ), and reliable electrochromic properties (multicolor, optical contrast and coloring efficiency of 33 % and 136 cm 2 C −1 at 450 nm). Further, we demonstrate the successful fabrication of a flexible electrochromic-supercapacitor device based on PTEPA , which can change the color from blue-green to violet, achieving monitoring of energy with favorable energy storage characteristics, and excellent stability against multiple charging/discharging and mechanical bending cycles. This structural design strategy may provide a new concept for developing cost-effective yet high-performance electrochromic-supercapacitor materials and devices.