The introduction of the redox couple of triiodide/iodide (I3−/I−) into aqueous rechargeable zinc batteries is a promising energy‐storage resource owing to its safety and cost‐effectiveness. Nevertheless, the limited lifespan of zinc–iodine (Zn–I2) batteries is currently far from satisfactory owing to the uncontrolled shuttling of triiodide and unfavorable side‐reactions on the Zn anode. Herein, space‐resolution Raman and micro‐IR spectroscopies reveal that the Zn anode suffers from corrosion induced by both water and iodine species. Then, a metal–organic framework (MOF) is exploited as an ionic sieve membrane to simultaneously resolve these problems for Zn–I2 batteries. The multifunctional MOF membrane, first, suppresses the shuttling of I3− and restrains related parasitic side‐reaction on the Zn anode. Furthermore, by regulating the electrolyte solvation structure, the MOF channels construct a unique electrolyte structure (more aggregative ion associations than in saturated electrolyte). With the concurrent improvement on both the iodine cathode and the Zn anode, Zn–I2 batteries achieve an ultralong lifespan (>6000 cycles), high capacity retention (84.6%), and high reversibility (Coulombic efficiency: 99.65%). This work not only systematically reveals the parasitic influence of free water and iodine species to the Zn anode, but also provides an efficient strategy to develop long‐life aqueous Zn–I2 batteries.

Li metal can potentially deliver much higher specific capacity than commercially used anodes. Nevertheless, because of its poor reversibility, abundant excess Li (usually more than three times) is required in Li metal batteries, leading to higher costs and decreased energy density. Here, a concentrated lithium bis(trifluoromethane sulfonyl) imide (LiTFSI)–lithium nitrate (LiNO3)–lithium bis(fluorosulfonyl)imide (LiFSI) ternary‐salts electrolyte is introduced to realize a high stable Li metal full‐cell with only a slight excess of Li. LiNO3 and LiFSI contribute to the formation of stable Li2O–LiF‐rich solid electrolyte interface layers, and LiTFSI helps to stabilize the electrolyte under high concentration. Li metal in the electrolyte remains stable over 450 cycles and the average Coulombic efficiency reaches 99.1%. Moreover, with 0.5 × excess Li metal, the Coulombic efficiency of Li metal in the LiTFSI–LiNO3–LiFSI reaches 99.4%. The electrolyte also presents high stability to the LiFePO4 cathode, the capacity retention after 500 cycles is 92.0% and the Coulombic efficiency is 99.8%. A Li metal full‐cell with only 0.44 × excess Li is also assembled, it remains stable over 70 cycles and 83% of the initial capacity is maintained after 100 cycles.

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Aqueous electrolytes offer major advantages in safe battery operation, green economy, and low production cost for advanced battery technology. However, strong water activity in aqueous electrolytes provokes a hydrogen evolution reaction and parasitic passivation on electrodes, leaving poor ion‐transport in the electrolyte/electrode interface. Herein, a zeolite molecular sieve‐modified (zeolite‐modified) aqueous electrolyte is proposed to reduce water activity and its side‐reaction. First, Raman spectroscopy reveals a highly aggressive solvation configuration and significantly suppressed water activity toward single water molecule. Then less hydrogen evolution and anti‐corrosion ability of zeolite‐modified electrolyte by simulation and electrochemical characterizations are identified. Consequently, a zinc (Zn) anode involves less side‐reaction, and develops into a compact deposition morphology, as proved by space‐resolution characterizations. Moreover, zeolite‐modified electrolyte favors cyclic life of symmetric Zn||Zn cells to 4765 h at 0.8 mA cm−2, zinc‐VO2 coin cell to 3000 cycles, and pouch cell to 100 cycles. Finally, the mature production technique and low‐cost of zeolite molecular sieve would tremendously favor the future scale‐up application in engineering aspect.