Benefiting from the high capacity of Zn metal anodes and intrinsic safety of aqueous electrolytes, rechargeable Zn ion batteries (ZIBs) show promising application in the post-lithium-ion period, exhibiting good safety, low cost, and high energy density. However, its commercialization still faces problems with low Coulombic efficiency and unsatisfied cycling performance due to the poor Zn/Zn²⁺ reversibility that occurred on the Zn anode. To improve the stability of the Zn anode, optimizing the Zn deposition behavior is an efficient way, which can enhance the subsequent striping efficiency and limit the dendrite growth. The Zn deposition is a controlled kinetics-diffusion joint process that is affected by various factors, such as the interaction between Zn²⁺ ions and Zn anodes, ion concentration gradient, and current distribution. In this review, from an electrochemical perspective, we first overview the factors affecting the Zn deposition behavior and summarize the modification principles. Subsequently, strategies proposed for interfacial modification and 3D structural design as well as the corresponding mechanisms are summarized. Finally, the existing challenges, perspectives on further development direction, and outlook for practical applications of ZIBs are proposed.

Achieving stable Zn-ion batteries operating under high charging–discharging rates and a high depth of discharge (DOD) remains challenging due to intensified dendrite growth and side reaction. This work introduces a novel hygroscopic vanadium metal–organic framework (V-MOF) as a multifunctional protective layer to achieve an outstanding Zn anode. The as-fabricated battery can remain stable and high performance with high DOD of 85.5% and fast discharging rate of 50 mAh/cm². The hygroscopic V-MOF nature removes solvated shells and captures water as bonded/iced water within its structure, significantly suppressing side reactions. In addition, the V-MOF coating optimized the electrical field, inhibited the cracks, and reduced the Zn dendrite formation even at a high rate of 50 mAh/cm², due to the construction of electrolyte-philic and smooth surface. Consequently, the hygroscopic Zn/V-MOF symmetrical cells achieve exceptional performance over 1000 h under 50 mA/cm² (50 mAh/cm²) with 85.5% DOD. The Zn/V-MOF||V₂O₃/NC cell shows a capacity of 267 mAh/g at 0.5 A/g with excellent rate capability (100 mAh/g @20 A/g). In addition, it achieves an outstanding lifetime over 3300 cycles @ 5 A/g. The results at high rates with high DOD highlight the magnificent potential of hygroscopic V-MOF to achieve outstanding Zn anode and large-scale aqueous batteries.

The design of efficient oxygen reductionreaction (ORR) catalyst with fast kinetics is crucial for high-performance Zn–air batteries but remains a challenge. Herein, inspired by the oxidative respiratory chain of prokaryotes, an ORR electrocatalyst is reported by mimicking the microstructure of Staphylococcus aureus and simitaneously utilizing this low-cost cell as the precursor. The catalyst consists of MnO₂/Co₂P nanocomposites support on Staphylococcus aureus-derived hollow spherical carbon, which not only accelerates electron transfer for improved intrinsic reaction kinetics, but also creates an OH⁻ concentration gradient for enhanced mass transfer efficiency. Such bio-inspired and derived ORR catalyst enables rechargeable Zn–air batteries with ultra-long cycling stability of more than 2800 h at a high capacity of 810.3 mAh g⁻¹, which is superior among the reported bio-derived oxygen catalysts. A flexible Zn–air battery based on the bio-inspired and derived catalyst is also assembled, and it well integrates with a wireless flexible electronic skin.