In Situ Growth of a Metal–Organic Framework-Based Solid Electrolyte Interphase for Highly Reversible Zn Anodes

Aqueous Zn ion batteries are receiving tremendous attention owing to their attractive features with respect to safety, cost, and scalability, yet their lifespan is severely limited by the poor reversibility of the Zn metal anode. Thereby, an artificial solid electrolyte interphase (ASEI) based on an anionic metal–organic framework (MOF) is in situ fabricated on the surface of Zn anodes. The robust ASEI protects the anode from side reactions and largely promotes its Coulombic efficiency during battery cycling. Owing to the high intrinsic Zn2+ conductivity and abundant zincophilic sites, it also facilitates enhanced Zn redox activities. More interestingly, the consecutive sulfonate groups in the MOF channels guide rapid and directional transport of Zn ions and thus endow a dendrite-free Zn plating/stripping lifespan of 5700 h at 2 mA cm–2. This work provides a fresh strategy to promote the performance of Zn and even other metallic anodes toward practical battery applications.