Novel Fe(ii) coordination polymers derived from V-shape terpyridine-based ligands for efficient electrochromism and supercapacitors

Abstract

Three novel terpyridine-Fe(II) coordination polymers (Fe–V-1, Fe–V-2, and Fe–V-3) were developed for electrochromism and energy storage. The desired coordination polymers demonstrated obvious and rapid color switching between purple and light yellow, with optical contrast of approximately 50%, short response time less than 1.4 s, high coloring efficiency up to 397.8 cm² C⁻¹, as well as good cycle stability. Moreover, the present coordination polymer thin films showed energy storage performance with the area specific capacitance values among 1.71–2.41 mF cm⁻² at a current density of 0.1 mA cm⁻². Furthermore, we fabricated electrochromic energy storage devices based on these coordination polymers, which exhibited noticeable color changes during their charging and discharging processes, suggesting their potential application prospects in energy-saving smart windows.