Dual-Band Electrochromic Supercapacitor Utilizing Metal-Organic Coordination Polymer with Multi-Redox Feature.

Electrochromic supercapacitors, which indicate energy states through optical color changes, are gaining significant attention for their potential in energy saving and recycling. In this study, a novel metal-organic coordination polymer (DTPB-MCP) is successfully synthesized using an N,N'-diphenyl-1,4-phenylenediamine (DTPB)-functionalized phenanthroline ligand. The resulting DTPB-MCP film demonstrated desirable electrochromic performance in both the visible light (ΔT:77.6% at 730 nm) and near-infrared (ΔT: 49.2% at 1410 nm) regions, as well as decent energy-storage capabilities (16.4 mF cm at 0.1 mA cm ), attributed to the presence of multiple redox centers. Furthermore, a hybrid electrochromic supercapacitor is also developed by combining DTPB-MCP with V₂O₅ (DTPB-MCP//V₂O₅), showcasing a significant optical contrast (47.6% at 750 nm and 14.5% at 1420 nm), an acceptable capacitance of 11.5 mF cm with good rate performance, and impressive cycling stability (maintaining 81% of capacitance after 2750 charging/discharging cycles). In addition, >60% of electric energy can be reused to drive small household appliances during the bleaching process. The design principles outlined in this study offer valuable insights into the development of high-performance dual-band electrochromic energy-storage materials, highlighting their potential applications in energy recovery and reuse.