In Situ Growth of 2D Metal–Organic Framework Ion Sieve Interphase for Reversible Zinc Anodes

Abstract

Zinc metal anodes are gaining popularity in aqueous electrochemical energy storage systems for their high safety, cost-effectiveness, and high capacity. However, the service life of zinc metal anodes is severely constrained by critical challenges, including dendrites, water-induced hydrogen evolution, and passivation. In this study, a protective two-dimensional metal–organic framework interphase is in situ constructed on the zinc anode surface with a novel gel vapor deposition method. The ultrathin interphase layer (~1 μm) is made of layer-stacking 2D nanosheets with angstrom-level pores of around 2.1 Å, which serves as an ion sieve to reject large solvent–ion pairs while homogenizes the transport of partially desolvated zinc ions, contributing to a uniform and highly reversible zinc deposition. With the shielding of the interphase layer, an ultra-stable zinc plating/stripping is achieved in symmetric cells with cycling over 1000 h at 0.5 mA cm⁻² and ~700 h at 1 mA cm⁻², far exceeding that of the bare zinc anodes (250 and 70 h). Furthermore, as a proof-of-concept demonstration, the full cell paired with MnO₂ cathode demonstrates improved rate performances and stable cycling (1200 cycles at 1 A g⁻¹). This work provides fresh insights into interphase design to promote the performance of zinc metal anodes.