Click Chemistry-Inspired Fixation Catalysis for Long-Life Zinc-Iodine Batteries.

Wang, Feifei; Ma, Runlin; Chen, Zihui; Yin, Tianyu; Yan, Zhijie; Chi, Sijia; Jiao, Menggai; Yang, Chunpeng et al. · Adv Mater · 2026

basic_science · Level V

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Abstract

Zinc-iodine (Zn-I<sub>2</sub>) 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)<sub>2</sub>)<sub>2</sub>-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<sub>2</sub> batteries deliver an exceptional cycling lifespan of 63 000 cycles at 20 A g<sup>-1</sup> with 95% capacity retention and ≈100% Coulombic efficiency. Remarkably, even under a high mass loading of 20 mg cm<sup>-2</sup> in pouch Zn-I<sub>2</sub> cells, the system maintains a high areal capacity of 3.3 mAh cm<sup>-2</sup> and ≈100% capacity retention even after 2000 cycles.