In Situ Construction of High‐Density Solid Electrolyte Interphase from MOFs for Advanced Zn Metal Anodes

Abstract Aqueous zinc anode has been re‐evaluated due to the superiority in tackling safety and cost concerns. However, the limited lifespan originating from Zn dendritic and side reactions largely hamper commercial development. Currently, the coating prepared by simple slurry mixing is leaky and ineffectively isolate sulfate and water. Herein, inspired by the DFT calculations and the easy hydrolysis characteristic of MIL‐125 (Ti), an in‐situ grown high‐dense TiO 2‐x solid electrolyte interphase (HDSEI) with rich oxygen vacancies is successfully constructed in an aqueous electrolyte, in which the oxygen vacancies not only strengthen the hydrogen binding force thereby inhibiting the hydrogen precipitation by‐reaction, but also reduce the migration energy barrier of zinc ions and enhance the mechanical properties. Profiting from the HDSEI, symmetric Zn cells survive up to remarkable 4200 h at 1 mA cm −2 , nearly 42‐times than that of bare Zn anodes. In situ optical microscopy clearly reveals that the in situ grown HDSEI homogenizes the zinc deposition process, while bare zinc without HDSEI shows significant dendrites, confirming the protective nature of HDSEI. Furthermore, full Zn ion capacitors can deliver excellent electrochemical performance, providing a feasible in situ approach to construct HDSEI to implement dendrite‐free metal anodes.