Tailoring an Ion-Sieving Interface to Boost Zn2+ Desolvation Kinetics for Dendrite-Free Zinc Anodes

Challenges of the active Zn anode, including dendrite growth and the competitive hydrogen evolution reaction (HER), have plagued the practical application of rechargeable aqueous zinc-ion batteries. In this paper, we have engineered 2D MOF5 nanoplanes to modify a dense artificial interface, effectively reducing ion diffusion distance and enhancing the charge transition rate and uniformity of local current density. Moreover, the pore size of MOF5-1 has been significantly reduced to 5.6 Å, which blocks solvated H2O molecules, thereby decreasing ion transfer resistance and enhancing kinetic performance. Our density functional theory calculations reveal a preferential Zn deposition on the Zn(001) substrate and demonstrate the capability of the 3D MOF5 framework to capture water molecules. This results in a uniform Zn2+ flux and impedes solvated water, thereby promoting efficient and reversible Zn plating/stripping processes. In situ optical microscopy and scanning electron microscopy confirm that the MOF5-1 coating significantly diminishes dendrite growth, boosts corrosion resistance, and mitigates HER. The symmetric cell of Zn@MOF5-1 maintains operations of up to 1200 h at 5 mA cm–2 and 1000 h at 20 mA cm–2. In addition, the Cu@MOF5-1//Zn asymmetric cell demonstrated an exceptional Coulombic efficiency of 99.7% after 650 cycles (1300 h). The full cell of Zn@MOF5-1//MnO2 delivers a notable capacity of 121.6 mAh g–1 at 2 A g–1 and demonstrates robust cycling stability (retaining 80.7% after 1100 cycles). This research offers fundamental insights into the design and development of efficient artificial interfaces for ultrastable aqueous zinc batteries.