A Biomimetic Copper Silicate-MOF Hybrid for Highly Stable Zn Metal Anode.

Abstract

To promote the electrochemical performance of aqueous zinc-ion batteries, various artificial interlayers are developed to mitigate dendrite growth and H₂O-induced side reactions of Zn anode. Metal-organic framework (MOF) interlayers show much potential in solving these problems, yet their practical usage is inhibited by their inferior structural stability during cycles. Herein, inspired by the biological mechanism and symbiotic architecture of drosera rotundifolia, this challenge is tackled by constructing a hierarchical hollow CuSiO₃-MOF hybrid through in situ MOF conversion. For protecting Zn anode, this biomimetic hybrid offers good structural stability, abundant zincophilic sites, strong desolvation capability, and fast ion migration, which collectively enable highly stable dendrite-free Zn plating/stripping processes and suppress H₂O-related side reactions. Consequently, the Zn@CuSiO₃-MOF symmetric battery achieves an ultralong lifespan exceeding 3500 h with low voltage hysteresis. Remarkably, it maintains stable cycling behaviors of 1200 and 400 h even under high depths of discharge of 45% and 90%, outperforming the most reported MOF-modified anodes. Moreover, full cells with MnO₂ and C@V₂O₃ cathodes exhibit exceptional cycling performance and rate capability, highlighting the practical applications of Zn@CuSiO₃-MOF anode for grid storage and wearable electronics. This bioinspired strategy provides a feasible approach to constructing stable MOF-based hybrid for high-performance Zn anode.