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Although Zn‐ion batteries have gained extensive attention, it persistently suffers from uncontrolled dendrite growth and severe side reactions on zinc (Zn) anodes. Here, a spirally grown 3D ZnCo overlayer is designed on one side of commercial zinc foil by means of constant‐current electrodeposition to address these challenges. In contrast to Zn crystal planes, the ZnCo crystal planes mainly exposed to the side of the 3D spiral structure exhibit superior zincophilicity, promoting the bottom‐up layer‐by‐layer Zn growth. During plating, the surface of Zn metal with ZnCo overlayer (ZnCo) gradually becomes flat by constraining the diffusion behavior of Zn2+ ions. The resulting ZnCo–ZnCo cells demonstrate stable operation for over 620 h at a large current density of 5 mA cm−2. Furthermore, the ZnCo‐NH4V4O10 pouch cell delivers an initial capacity of 190 mA h g−1 and maintains a high capacity retention of 81% after 400 cycles. This alloying strategy of electro‐deposition offers new insights into the design of highly reversible Zn anodes. [ABSTRACT FROM AUTHOR]

Layer‐structured metal vanadates have attracted extensive attention as cathode materials due to multi‐electron redox reactions and versatile cations storage capability. Nevertheless, their actual promotion is still hindered by the sluggish reaction kinetics and inferior phase transition upon repeated cations (de)intercalation. Here, large‐sized NH4+ is introduced into the K‐site of K0.43(NH4)0.12V2O5–δ to enable more kinetically favorable oxygen vacancies. The reinforced structure ensures complete solid‐solution phase transition and buffers the dramatic structural change upon potassium storage. The stable presence of NH4+ as pillars during cycling is also confirmed. Meanwhile, the oxygen vacancies induced by alkali‐site substitution can facilitate ion diffusion and enhance the electronic conductivity, as further demonstrated by theoretical calculations. Therefore, it exhibits a high capacity of 117.8 mA g−1 at 20 mA g−1 with smooth profiles and superior capacity retention of 92.5% after 800 cycles at 1000 mA g−1. Such an effective synergetic strategy also promotes its zinc storage capability, which performs negligible self‐discharge behavior and retains a reversible capacity of 216.8 mAh g−1 after 3000 cycles at 10 A g−1. This synergetic strategy may provide novel perspectives to develop layer‐structured cathode and facilitate its practical application in energy storage devices. [ABSTRACT FROM AUTHOR]