devices to allow energy release at night and for continuous supply under low wind conditions. The most prevalent type of secondary energy storage uses lithiumion batteries (LIBs), that possess high energy density and long cycle life and have brought about a remarkable technical revolution for portable electronics, vehicles, and many other aspects in daily life. [1] However, considering the growing cost of the limited lithium resources and safety concerns derived from intrinsic chemical activity of metallic lithium and its combustible ester electrolytes, aqueous rechargeable batteries have been recently spotlighted as promising alternatives especially for utilization of large-scale energy storage stations. [2] Among them, aqueous zinc-ion batteries (AZIBs) have gained exceptional interest in aqueous systems due to the beneficial physicochemical properties of zinc, that is, i) a high theoretical volumetric capacity around 5585 mAh cm −3 of a metallic zinc anode compared with 2061 mAh cm −3 and 1129 mAh cm −3 for lithium and sodium anodes, respectively; ii) low redox potential of −0.762 V versus standard hydrogen electrode, and iii) electrochemical stability of metallic zinc in its sulfate solutions at near neutral or slightly acidic aqueous electrolyte providing the batteries with safe, costeffective, and environment-friendly characteristics. [3][4][5][6] Cost-effective and environmentally-friendly aqueous zinc-ion batteries (AZIBs) exhibit tremendous potential for application in grid-scale energy storage systems but are limited by suitable cathode materials. Hydrated vanadium bronzes have gained significant attention for AZIBs and can be produced with a range of different pre-intercalated ions, allowing their properties to be optimized. However, gaining a detailed understanding of the energy storage mechanisms within these cathode materials remains a great challenge due to their complex crystallographic frameworks, limiting rational design from the perspective of enhanced Zn 2+ diffusion over multiple length scales. Herein, a new class of hydrated porous δ-Ni 0.25 V 2 O 5 .nH 2 O nanoribbons for use as an AZIB cathode is reported. The cathode delivers reversibility showing 402 mAh g −1 at 0.2 A g −1 and a capacity retention of 98% over 1200 cycles at 5 A g −1 . A detailed investigation using experimental and computational approaches reveal that the host "δ" vanadate lattice has favorable Zn 2+ diffusion properties, arising from the atomic-level structure of the well-defined lattice channels. Furthermore, the microstructure of the as-prepared cathodes is examined using multi-length scale X-ray computed tomography for the first time in AZIBs and the effective diffusion coefficient is obtained by imagebased modeling, illustrating favorable porosity and satisfactory tortuosity.

The search for new nanostructural topologies composed of elemental carbon is driven by technological opportunities as well as the need to understand the structure and evolution of carbon materials formed by planetary shock impact events and in laboratory syntheses. We describe two new families of diamond-graphene (diaphite) phases constructed from layered and bonded sp3 and sp2 nanostructural units and provide a framework for classifying the members of this new class of materials. The nanocomposite structures are identified within both natural impact diamonds and laboratory-shocked samples and possess diffraction features that have previously been assigned to lonsdaleite and postgraphite phases. The diaphite nanocomposites represent a new class of high-performance carbon materials that are predicted to combine the superhard qualities of diamond with high fracture toughness and ductility enabled by the graphitic units and the atomically defined interfaces between the sp3- and sp2-bonded nanodomains.

Complex nanostructures in diamondMeteoritic diamonds formed during bolide impacts on Earth and diamond-related materials synthesized by compressing graphite contain a wide variety of complex nanostructures. This Comment highlights and classifies this structural complexity by a systematic hierarchical approach, and discusses the perspectives on nanostructure and properties engineering of diamond-related materials.

The primary issue faced by MnO2 cathode materials for aqueous Zn-ion batteries (AZIBs) is the occurrence of structural transformations during cycling, resulting in unstable capacity output. Pre-intercalating closely bonded ions...