Molecular Filter Net Synergy with Regulation in Ion Percolation for High-Performance Zn Metal Batteries

The uncontrollable dendrite growth and complex parasitic reactions of Zn metal anodes cause short cycle lives and low Coulombic efficiency, which seriously affect their applications. To address these issues, this research proposes an efficient ion percolating interface constituted by a hydrogen-bonded organic framework (HND) for a highly stable and reversible Zn anode. The hydrogen-bonded skeleton acts as a molecular filter net, capturing water molecules by forming targeted hydrogen-bonding systems with them, sufficiently inhibiting parasitic reactions. Additionally, the interaction of the rich-N and -O electrochemically active sites with Zn²⁺ effectively regulates its percolation, which greatly enhances the diffusion kinetics of Zn²⁺, thus facilitating rapid and uniform migration of Zn²⁺ at the anode surface. Through the above synergistic effect, dendrite-free anodes with highly reversible Zn plating/stripping behaviors can be achieved. Hence, the modified Zn anode (HND@Zn) performs a steady cycling time of more than 1700 h at 1 mA cm^-2. Moreover, the HND@Cu||Zn asymmetric cell exhibits a stable charge/discharge process of over 1600 cycles with an average Coulombic efficiency of up to 99.6% at 5 mA cm^-2. This work provides some conceptions for the evolution and application of high-performance Zn metal batteries.