Rechargeable aqueous zinc‐ion batteries (ZIBs) featuring the merits of low cost, eco‐friendliness, and enhanced safety have attracted extensive interests and considered as the most promising energy storage system. However, much efforts are devoted to the exploration of cathode materials and their storage mechanisms in this system, and inadequate attentions are received in regard to anode side especially in neutral or mild acidic electrolyte. Therefore, in this review, the fundamental understanding of existing issues including dendrite formation, corrosion, and hydrogen evolution are mainly revealed, as well as their interaction in neutral or mild acidic medium. In addition, the currently existing solution strategies on the anode are summarized and the mechanisms that contained are simultaneously investigated. Finally, perspectives on future anode modification and innovation direction are provided for the further development and research of Zn‐based ZIBs.

Aqueous Zn-ion batteries (ZIBs) are promising safe energy storage systems that have received considerable attention in recent years. Based on the electrochemical behavior of Zn 2+ in the charging and discharging process, herein we review the research progress on anode materials for use in aqueous ZIBs based on two aspects: Zn deposition and Zn 2+ intercalation. To date, Zn dendrite, corrosion, and passivation issues have restricted the development of aqueous ZIBs. However, many strategies have been developed, including structural design, interface protection of the Zn anode, Zn alloying, and using polymer electrolytes. The main aim is to stabilize the Zn stripping/plating layer and limit side reactions. Zn 2+ -intercalated anodes, with a high Zn 2+ storage capacity to replace the current metal Zn anode, are also a potential option. Finally, some suggestions have been put forward for the subsequent optimization strategy, which are expected to promote further development of aqueous ZIBs.

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Metal zinc, with the advantages of low cost, low redox potential, and high capacity, is an ideal anode for aqueous zinc-ion batteries. Nonetheless, the inferior plating/stripping Coulombic efficiency and poor reversibility hinder its practical applications. To address the drawbacks, the zinc nucleation overpotential of different substrates is systematically investigated in asymmetric cells for the first time to confirm the suitable substrate with highly reversible plating/stripping behavior. As a result, Cu foam presents the low zinc nucleation overpotential of 65.2 mV and superior plating/stripping Coulombic efficiency close to 100%. Meanwhile, Cu foam is optimized as the carrier for the deposition of metallic zinc and the preparation of the Zn@Cu foam anode through the electrochemical deposition method. Besides, the Zn@Cu foam anode holds the low initial polarization voltage and stable voltage hysteresis profile with negligible voltage polarization in the symmetric cell. Furthermore, coupled with the β-MnO2 cathode, it could exhibit an outstanding cycling ability with a capacity of 172.8 mA h g–1 after 600 cycles at 1 A g–1 in the full cell, corresponding to an extremely low decay rate of 0.0218% per cycle.

Many optimization strategies have been employed to stabilize zinc anodes of zinc-ion batteries (ZIBs). Although these commonly used strategies can improve anode performance, they simultaneously induce specific issues at the same time. In this study, through the combination of structural design, interface modification, and electrolyte optimization, an ‘all-in-one’ (AIO) electrode was developed. Compared to the three-dimensional (3D) anode in routine liquid electrolytes, the new AIO electrode can greatly suppress gas evolution and the occurrence of side reactions induced by active water molecules, while retaining the merits of a 3D anode. Moreover, the integrated AIO strategy achieves a sufficient electrode/electrolyte interface contact area, so that the electrode can promote electron/ion transfer, and ensure a fast and complete redox reaction. As a result, it achieves excellent shelving-restoring ability (60 h, four times) and 1200 cycles of long-term stability without apparent polarization. When paired with two common cathode materials used in ZIBs (α-MnO2 and NH4V4O10), full batteries with the AIO electrode demonstrate high capacity and good stability. The strategy of the ‘all-in-one’ architectural design is enlightened to solve the issues of zinc anodes in advanced Zn-based batteries.