Interfacial decoupling of ion–electron transport by an ultrathin N-doped holey graphene oxide coating for stable Zn metal anodes

초록

The electrochemical stability of zinc metal anodes is critically governed by coupled ion–electron transport at the electrode–electrolyte interface, which often leads to non-uniform deposition, dendrite growth, and parasitic side reactions in aqueous systems. Herein, we report an ultrathin (∼25 nm) N-doped holey graphene oxide (NHGO) coating that stabilizes Zn metal anodes through interfacial transport regulation rather than bulk passivation. The engineered NHGO layer integrates nanoscale porosity with nitrogen-doped graphene domains, enabling rapid Zn2+ transport while moderating electronic conductivity at the Zn surface. This decoupling of ion and electron transport promotes uniform subsurface Zn deposition and suppresses surface-localized plating, dendrite formation, and hydrogen evolution. As a result, the NHGO-coated Zn anode exhibits markedly enhanced interfacial stability, delivering long-term dendrite-free cycling in Zn//Zn symmetric cells and improved reversibility in Zn//Cu configurations. Structural and surface analyses reveal that the ultrathin coating maintains intimate contact with the Zn surface while preserving transport selectivity throughout extended cycling. This work demonstrates a surface-engineering strategy in which nanoscale control of charge transport pathways enables stable metal–electrolyte interfaces, offering a broadly applicable framework for regulating electrochemical reactions at reactive metal surfaces.

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