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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.

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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.

premise of guaranteeing electrochemical stability upon cycling. [2] Not rigidly limited to conventional redox reactions based on transition metal (TM) centers, redox activity centered at the oxide anions is emergently viewed as a promising strategy to effectively increase the energy density of SIBs. [3] When conventional cationic and novel anionic activities are triggered simultaneously, several cathodes delivering boosted capacities break the shackle of reversible TM redox couples. [4] As a representative example, Mn-based layered cathodes Na x [M y Mn 1−y ]O 2 (M = Li, Mg and Zn) deliver considerable capacity in the initial discharge process by employing the Mn-based and oxygen-related redox reactions simultaneously. [5] Based on the experience of Li-rich layered cathode materials, the utilization of these attractive anionic redox capacities would accompany harmful irreversible processes induced by excessive oxygen oxidation during charging process. [6] More importantly, irreversible lattice oxygen loss inevitably triggers deleterious migration of TM and structural distortion upon cycling, resulting in capacity decay, fading of the output potential and sluggish kinetics. [7] Therefore, the foremost challenge would focus on not only triggering unconventional anionic redox capacity but also stabilizing reversible these oxygen-related reactions. [5d,8] However, puzzled by foggy charge compensation mechanism between TM based and oxygenrelated redox processes, it is difficult to identify the reversible and irreversible anionic redox reactions. [9] Specifically, based on typically obtained "S-shape" discharge voltage profiles, no distinct boundary between TM and oxygen reduction reactions can be observed. [5b,10] More importantly, despite the existence of undesirable lattice oxygen loss during charging, high discharge capacities can still be obtained, which are actually caused by a reduction of TM couples beyond the pristine state. [9,11] In this case, comprehensive and in-depth characterizations including the valence change of TM and oxygen, O 2 evolution, surface/ bulk oxygen states, among others, are required to make a clear assignment of TM-based and oxygen-related redox capacity, which is essentially helpful for the development of anionic redox activity and inform subsequent materials selection. [3c,5a,12] Furthermore, in sodium-ion batteries, the trigger of anionic redox reactions is typically by the introduction of NaOM configuration, in which M is defined as the Li, Na, Mg and Zn within TM layer. [4c,5a,8,12c,13] Meanwhile, the Tarascon group has proved that lowering the energy of the transition metal d Triggering oxygen-related activity is demonstrated as a promising strategy to effectively boost energy density of layered cathodes for sodium-ion batteries. However, irreversible lattice oxygen loss will induce detrimental structure distortion, resulting in voltage decay and cycle degradation. Herein, a layered structure P2-type Na 0.66 Li 0.22 Ru 0.78 O 2 cathode is designed, delivering reversible ...

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