A V⁴⁺-V₂O₅ cathode with mixed vanadium valences was prepared via a novel synthetic method using VOOH as the precursor, and its zinc-ion storage performance was evaluated. The products are hollow spheres consisting of nanoflakes. The V⁴⁺-V₂O₅ cathode exhibits a prominent cycling performance, with a specific capacity of 140 mAh g⁻¹ after 1000 cycles at 10 A g⁻¹, and an excellent rate capability. The good electrochemical performance is attributed to the presence of V⁴⁺, which leads to higher electrochemical activity, lower polarization, faster ion diffusion, and higher electrical conductivity than V₂O₅ without V⁴⁺. This engineering strategy of valence state manipulation may pave the way for designing high-performance cathodes for elucidating advanced battery chemistry.

We report a binder-free stainless steel welded mesh@flower-like Mn₃O₄ composite with high zinc storage capability for aqueous zinc-ion batteries.

Biphasic and multiphasic compounds have been well clarified to achieve extraordinary electrochemical properties as advanced energy storage materials. Yet the role of phase boundaries in improving the performance is remained to be illustrated. Herein, we reported the biphasic vanadate, that is, Na_1.2V₃O₈/K₂V₆O₁₆·1.5H₂O (designated as Na_0.5K_0.5VO), and detected the novel interfacial adsorption–insertion mechanism induced by phase boundaries. First‐principles calculations indicated that large amount of Zn²⁺ and H⁺ ions would be absorbed by the phase boundaries and most of them would insert into the host structure, which not only promote the specific capacity, but also effectively reduce diffusion energy barrier toward faster reaction kinetics. Driven by this advanced interfacial adsorption–insertion mechanism, the aqueous Zn/Na_0.5K_0.5VO is able to perform excellent rate capability as well as long‐term cycling performance. A stable capacity of 267 mA h g⁻¹ after 800 cycles at 5 A g⁻¹ can be achieved. The discovery of this mechanism is beneficial to understand the performance enhancement mechanism of biphasic and multiphasic compounds as well as pave pathway for the strategic design of high‐performance energy storage materials. image