Metallo-Supramolecular Polymer Nanostructure with Exfoliated Molybdenum Disulfide Enabling Scalable Dual-Ion Electrochromic Energy Storage

Innovative electrochromic supercapacitors (ECSCDs) are gaining attention for their capability to alter optical hue during the redox process. At the same time, the scalability of smart window-based ECESD with low cost, durability, and environmentally compatible sodium-ion technology within ECESD is very important for practical applications. The judicious formation of easy-to-process nanoarchitectures with enhanced dual-ion dynamics can solve the challenge. Herein, by incorporating exfoliated 2D MoS 2 layers into a Fe-containing metallo-supramolecular polymer (MSP), PolyFe, the morphology changes to assembled nanorods, increasing thermal stability, ionic conductivity, and structural reinforcement in PolyFe-MoS 2 composites. The electrochemical study of the PolyFe-MoS 2 composite reveals the lowest charge-transfer resistance and a higher energy storage capacity compared with the PolyFe counterpart. A hybrid asymmetric sodium-ion ECSCD composed of PolyFe-MoS 2 and NiHCF electrodes exhibited faster color switching, with bleaching times of 2.6 s and coloring times of 1.1 s, along with a high coloration efficiency (829.1 cm 2 C -1 ) and a specific capacity of 30.3 mAh/g. Additionally, it demonstrates 86% retention of the initial optical contrast after 8000 EC cycles and only 2% degradation in Coulombic efficiency after 12,000 charge–discharge cycles. Importantly, PolyFe-MoS 2 ECSCD enables real-time, visual recognition of the stored energy level through distinct color changes. Furthermore, demonstrating a large-scale ECSCD (100 cm 2 ) underscores the material’s strong potential for real-world and commercial applications such as smart windows.