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.