Rational engineering of chiral Ni-based layered double hydroxide electrocatalysts with enhanced oxygen evolution reaction enabling high-performance Zn-air battery

초록

Regulating electron spin orientation provides a fundamentally new avenue to enhance electrocatalysis beyond conventional engineering strategies. In this work, we introduce the chirality-induced spin selectivity (CISS) effect as an effective quantum-level design principle to accelerate the oxygen evolution reaction (OER) and enable high-performance Zn-air batteries (ZABs). By incorporating the CISS effect into NiM layered double hydroxides (LDHs, M = Fe, V, Co, Al), we demonstrate that the ionic radius and electron configuration of trivalent metal cations critically govern the magnitude of the CISS effect. In particular, the incorporation of Fe3+ with a large ionic radius induces significant lattice distortion that promotes a chiral arrangement conducive to the generation of strong helical electric fields. Simultaneously, the high unpaired electron density of Fe3+ enhances spinselective electron transport. These synergistic effects maximize spin polarization and yield a chiral NiFe LDH electrocatalyst with markedly accelerated OER kinetics and suppressed singlet oxygen byproducts. When integrated into ZABs, this electrocatalyst achieves outstanding cycling stability with a minimal increase in charge voltage over 1200 h in alkaline electrolyte and 360 h in near-neutral electrolyte. This study introduces a novel paradigm for the development of advanced chiral electrocatalysts, offering mechanistic insights and practical opportunities for ZAB applications.

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