Gelation-Free Synthesis of Hyperbranched Triphenylamine Polymer: Multifunctional Conjugated Electrochromic Polymers...

Multifunctional electrochromic (EC) materials integrating optical modulation, energy storage, and thermal management are vital for next-generation smart windows. Overcoming the challenge of achieving high transparency, structural precision, and redox stability in a single polymer, we report a gelation-free hyperbranched conjugated poly(fluorene-alt-triphenylamine) (P(Fl-alt-TPA)) with a 100% degree of branching (DB). Synthesized via Suzuki-Miyaura polycondensation, it achieves high molecular weight without gelation, thereby overcoming the limitations of conventional A₂ + B₃. An electrochromic supercapacitor based on this polymer exhibits high energy and power densities, successfully powering an LED and a timer for over 5 and 6 min, respectively. Remarkably, it maintains 80.6% capacity retention after 10 000 cycles. Furthermore, in device applications, it demonstrates pronounced NIR heat-shielding (achieving a CR_NIR of 91.9% and suppressing a water temperature rise by 60.7%) and distinct electrofluorochromism (with a contrast ratio of 177). These results highlight that precise engineering of high-molecular-weight hyperbranched conjugated polymers (CPs) without gelation effectively integrates transparency, electrochromism, energy storage, heat shielding, and fluorescence switching into a single platform for advanced smart windows and multifunctional optoelectrochemical applications.