Artificial Solid Electrolyte Interphases with Confined Ion Channels and Zincophilic Sites for High-Performance Zn Metal Anodes

In the quest to overcome the obstacles encountered by zinc anodes and side reactions in aqueous zinc-ion batteries (AZIBs), researchers have presented a variety of innovative strategies. This research focuses on an approach by engineering angstrom pores (4.32 Å-8.57 Å), to serve as ion channels that selectively restrict the transport of [Zn(H₂O)₆]²⁺ ions based on size exclusion principles. Moreover, the utilization of nitrogen-enriched MET-6 as zincophilic sites enhances the adsorption of Zn²⁺ ions, thereby facilitating their desolvation process. Through rigorous experimental analysis and corroborated by computational simulations, it was demonstrated that the MET-6@Zn composite, serving as an artificial solid electrolyte interphase, can effectively suppress side reactions and ensure the maintenance of homogeneous electric fields and ion fluxes, which directed the uniform deposition of Zn²⁺ ions and realized high-performance Zn metal anodes. Notably, symmetric cells integrated with MET-6@Zn electrodes exhibited remarkable stability with continuous cycling for up to 3200 h at a current density of 0.5 mA cm^-2. In addition, full cells equipped with KVOH cathodes maintained an impressive capacity retention rate, retaining up to 82% of their initial capacity after 1250 cycles at a current density of 8 A g^-1, marking a substantial enhancement in comparison to the performance of bare zinc electrodes. The integration of confined ion channels and zincophilic sites presents a promising strategy for stabilizing zinc anodes, providing innovative solutions to persistent challenges in AZIB technology.