Click Chemistry‐Inspired Fixation Catalysis for Long‐Life Zinc–Iodine Batteries

Abstract

Abstract Zinc–iodine (Zn–I 2 ) batteries are promising candidates for high‐performance and cost‐effective energy storage, yet their practical deployment is hindered by severe polyiodide shuttling and limited redox kinetics. To overcome this bottleneck at its core, a molecular‐level fixation catalysis strategy—inspired by click chemistry principles is presented—that transcends the limitations of conventional adsorption and heterogeneous catalysis. Inspired by the selectivity and efficiency of click reactions, a Cp(Fe(CO) 2 ) 2 ‐derived molecular catalyst (Fe‐Cp) is designed that forms directional and robust Fe─I coordination bonds, locking iodine species into stable Fe‐CpI complexes. Beyond anchoring, Fe‐Cp uniquely enables axial electron transfer, facilitating reversible charge redistribution and dynamic iodine redox conversion beyond the reach of surface‐confined systems. This dual‐function mechanism not only suppresses the polyiodide shuttle but also dynamically regulates the electron redistribution at the catalytic interface, fundamentally enhancing reaction kinetics. Benefiting from this design, the Zn–I 2 batteries deliver an exceptional cycling lifespan of 63 000 cycles at 20 A g −1 with 95% capacity retention and ≈100% Coulombic efficiency. Remarkably, even under a high mass loading of 20 mg cm −2 in pouch Zn–I 2 cells, the system maintains a high areal capacity of 3.3 mAh cm −2 and ≈100% capacity retention even after 2000 cycles.