Synergistic Interfacial Anchoring and Defect Regulation via SAMs for Highly Stable Flexible Electrochromic Energy Storage Devices

ABSTRACT Flexible electrochromic energy storage devices (FECESDs) are highly promising for wearable electronics, integrating tunable optoelectronic properties with efficient energy storage. However, weak interfacial chemical anchoring and resultant mechanical delamination between the electrode and active material during long‐term cycling remain critical bottlenecks. Using Prussian blue analogues (PBAs) as a model, we report a fabrication strategy that synergizes interfacial chemical bonding and crystallization kinetics. This approach seeks to utilize SAMs as kinetically active templates rather than mere static anchors. By pre‐seeding Fe 3+ nucleation centers at 3‐mercaptopropionic acid termini, our structural characterizations suggest that an oriented growth of PBAs is achieved on porous nylon/Au substrates. Concurrent refinement of interfacial anchoring and lattice perfection significantly bolsters the mechanical integrity and electrochemical stability of the active materials. PBAs‐based FECESDs deliver a specific capacity of 218.9 mAh g −1 at 0.5 A g −1 with 85.2% retention at 5.0 A g −1 . Enhanced interfacial coupling ensures 97.3% capacity retention over 10 000 cycles under continuous 60° bending. Beyond energy storage, synchronized color transitions enable real‐time visual state‐of‐charge monitoring and robust adaptive camouflage. This strategy provides a versatile framework for reliable, high‐performance FECESDs across diverse application scenarios.