Optimizing Porous Metal–Organic Layers for Stable Zinc Anodes

Aqueous zinc-ion batteries (ZIBs) have been considered as alternative stationary energy storage systems, but the dendrite and corrosion issues of Zn anodes hinder their practical applications. Here we report a series of two-dimensional (2D) metal–organic frameworks (MOFs) with Zr 12 clusters, which act as artificial solid electrolyte interphase (SEI) layers to prevent dendrites and corrosion of Zn anodes. The Zr 12 -based 2D MOF layers were formed by incubating 3D layer-pillared Zr-MOFs in ZnSO 4 aqueous electrolytes, which replaced the pillar ligands with terminal SO4 2– . Furthermore, the pore sizes of Zr 12 -based 2D MOF layers were systematically tuned, leading to optimized Zn 2+ conduction properties and protective performance for Zn anodes. In contrast to the traditional 2D-MOFs with Zr 6 clusters, Zr 12 -based 2D MOF layers as artificial SEI significantly reduced the polarization and increased the stability of Zn anodes in MOF@Zn||MOF@Zn symmetric cells and MOF@Zn||MnO 2 full cells. In situ experiments and DFT computations reveal that the enhanced cell performance is attributed to the unique Zr 12 -based layered structure with intrinsic pores to allow fast Zn 2+ diffusion, surface Zr-SO 4 zincophilic sites to induce uniform Zn deposition, and inhibited hydrogen evolution by 2D MOF Zr 12 layers.