The working principles of interphase strategies to enhance Zn reversibility are discussed. The effectiveness evaluation techniques, including electrochemical methods, characterization measurements, and computational simulations, are proposed.

We report a bio-inspired design strategy for constructing anin situpolymeric SEI in aqueous Zn chemistry. This SEI can restrain interfacial side reactions, facilitate a uniform Zn²⁺flux, and consequently endow a highly stable Zn metal anode.

This Review outlines advancements in cathodes beyond Zn²⁺ intercalation for aqueous Zn batteries, assesses the challenges in transitioning from laboratory research to industrial application, and identifies promising candidates for practical use.

In this work, I⁻ poisoning mechanism is proposed for SACs selection to suppress shuttle effect in Zn–I₂ batteries. It is found that I⁻ formation and desorption are crucial to maintain the catalytic and adsorption role of metallic element.

As a burgeoning electrolyte system, eutectic electrolytes based on ZnCl₂/Zn(CF₃SO₃)₂/Zn(TFSI)₂ have been widely proposed in advanced Zn‐I₂ batteries; however, safety and cost concerns significantly limit their applications. Here, we report new‐type ZnSO₄‐based eutectic electrolytes that are both safe and cost‐effective. Their universality is evident in various solvents of polyhydric alcohols, in which multiple −OH groups not only involve in Zn²⁺ solvation but also interact with water, resulting in the high stability of electrolytes. Taking propylene glycol‐based hydrated eutectic electrolyte as an example, it features significant advantages in non‐flammability and low price that is <1/200 cost of Zn(CF₃SO₃)₂/Zn(TFSI)₂‐based eutectic electrolytes. Moreover, its effectiveness in confining the shuttle effects of I₂ cathode and side reactions of Zn anodes is evidenced, resulting in Zn‐I₂ cells with high reversibility at 1 C and 91.4 % capacity remaining under 20 C. After scaling up to the pouch cell with a record mass loading of 33.3 mg cm⁻², super‐high‐capacity retention of 96.7 % is achieved after 500 cycles, which exceeds other aqueous counterparts. This work significantly broadens the eutectic electrolyte family for advanced Zn battery design.