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Single‐atom Fe‐N‐C (denoted as Fe1‐N‐C) catalysts exhibit inadequate bifunctional activities to conquer the sluggish oxygen reduction and evolution reaction (ORR/OER), hindering their practical applications in rechargeable Zn‐air batteries (ZABs). Here, by employing Fe1‐N‐C hollow nanorods as ORR‐active support, OER‐active NiFe‐layered double hydroxide (NiFe‐LDH) nanodots are evenly decorated through a spatially confined process to form NiFe‐LDH/Fe1‐N‐C heterostructure hollow nanorods with abundant accessible catalytic sites. The NiFe‐LDH/Fe1‐N‐C heterostructure not only enhances the ORR activity of pristine Fe1‐N‐C but also realizes efficient bifunctional ORR/OER activity in one monolithic catalyst. Theoretical calculations reveal that introducing NiFe‐LDH nanodots results in donation of electrons to the Fe1‐N‐C matrix and thus lowers the Fe‐d band center of the Fe‐N4 sites, dramatically narrowing the energy barriers of the ORR rate‐limiting steps. As a result, NiFe‐LDH/Fe1‐N‐C nanorods deliver remarkable ORR activity with a half‐wave potential of 0.90 V versus reversible hydrogen electrode, surpassing bare Fe1‐N‐C and commercial Pt/C. Impressively, the integrated NiFe‐LDH/Fe1‐N‐C catalysts show outstanding bifunctional performance with a small overpotential gap of only 0.65 V. The liquid‐state ZABs with NiFe‐LDH/Fe1‐N‐C as an air‐cathode catalyst deliver a peak power density of 205 mW cm−2 and long‐term cycling stability of up to 400 h. [ABSTRACT FROM AUTHOR]

An aqueous Zn/VS2 battery is designed, which consists of a VS2 cathode, a zinc anode, and a mild ZnSO4 aqueous electrolyte. The battery delivers a high capacity, and exhibits long‐term cyclic stability due to the large layer spacing and high conductivity of VS2. A reversible insertion/extraction of Zn2+ is observed during the discharge/charge process. [ABSTRACT FROM AUTHOR]

Niobium pentoxides (Nb2O5) have attracted extensive interest for ultrafast lithium‐ion batteries due to their impressive rate/capacity performance and high safety as intercalation anodes. However, the intrinsic insulating properties and unrevealed mechanisms of complex phases limit their further applications. Here, a facile and efficient method is developed to construct three typical carbon‐confined Nb2O5 (TT‐Nb2O5@C, T‐Nb2O5@C, and H‐Nb2O5@C) nanoparticles via a mismatched coordination reaction during the solvothermal process and subsequent controlled heat treatment, and different phase effects are investigated on their lithium storage properties on the basis of both experimental and computational approaches. The thin carbon coating and nanoscale size can endow Nb2O5 with a high surface area, high conductivity, and short diffusion length. As a proof‐of‐concept application, when employed as LIB anode materials, the resulting T‐Nb2O5@C nanoparticles display higher rate capability and better cycling stability as compared with TT‐Nb2O5@C and H‐Nb2O5@C nanoparticles. Furthermore, a synergistic effect is investigated and demonstrated between fast diffusion pathways and stable hosts in T‐Nb2O5 for ultrafast and stable lithium storage, based on crystal structure analysis, in situ X‐ray diffraction analysis, and density functional theoretical calculations. Therefore, the proposed synthetic strategy and obtained deep insights will stimulate the development of Nb2O5 for ultrafast and long‐life LIBs. [ABSTRACT FROM AUTHOR]