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would impose restrictions on the penetration of LIBs into these large-volume markets. [3,4] In addition, after 25 years of continuous improvements, the mature LIBs technology is approaching a fundamental limit in terms of energy density (slightly above 300 W h kg −1 ) and costs at the materials level. [4][5][6] With the aforementioned concerns, alternative battery concepts have significantly stimulated research interests to further drive battery technologies to increase both the gravimetric and volumetric energy densities, reduce the cost, and expand the cycling life. [3,6,7] The "beyond Li-ion" technologies such as lithium-air, lithium-sulfur (Li-S), multivalent batteries, and solid-state batteries show the unique feature of using metal anodes that can store more energy via a reversible metal plating/stripping process. Unfortunately, these emerging or reviving technologies involving lithium metal inevitably meet the critical challenges of resource shortage. Furthermore, the high reactivity of lithium metal leads to electrolyte consumption and nonuniform lithium distribution (even dendritic growth) during cycling. These issues still hamper the mainstream commercialization of the lithium-metal-based batteries. [8,9] Rechargeable magnesium (Mg) batteries may offer considerable advantages (see Table 1) over Li-metal batteries because the metallic Mg anode shows double the volumetric capacity, safer and easier processing features, more uniform and nondendritic electroplating during cell charging, and cheaper costs due to its greater abundance in the earth crust. [4,[10][11][12][13] Based on these advantages, intensive attention has been garnered toward the development of new electrolytes, cathodes, and their corresponding mechanistic understandings for the rechargeable Mg batteries. Additionally, several industries including Pellion Technologies (a spin-off company from Massachusetts Institute of Technology), the Toyota Research Institute of North America, and recently Sony Corporation have initiated R&D projects for the rechargeable Mg batteries and tried to find practical application pathways. Nonetheless, developing a high-energy-density Mg battery with long cycle life and high rate capability is still a huge challenge due to the lack of high-performance cathodes and suitable Mg-ion electrolytes. [9,12] It is fair to state that the Chevrel phases, reported by Aurbach et al. in 2000, are still the most attractive Mg-ion Rechargeable magnesium (Mg) batteries are one of the potential contenders to replace current Li-ion batteries to power future electric vehicles with lower cost, higher safety, and extended mileage. To achieve this goal, both high-voltage intercalation-type cathodes and high-capacity conversion-type cathodes are considered. However, there are still no reports to compare rechargeable Mg batteries with the state-of-the art Li-ion batteries in terms of their overall performance. Also, potential cathode materials to deliver higher energy density in rechargeable Mg batteries are rarely summarized. Here, t...

Orthorhombic V(2)O(5) single-crystalline nanobelts with widths of 100-300 nm, thicknesses of 30-40 nm, and lengths up to tens of micrometers have been synthesized on a large scale in a hydrogen peroxide aqueous solution by an environmentally friendly chemical route. Such nanobelts grow along the direction of [010]. The influence of the reaction time on the crystal structures and morphologies of the resulting products are investigated. A probable dehydration-recrystallization-cleavage mechanism for the formation of V(2)O(5) nanobelts is proposed. The experiments demonstrate that the use of a nanosized belt-like structure can considerably enhance the specific discharge capacity in lithium-ion batteries.

Building heterostructures containing dissimilar coupling components with different bandgaps can promote interfacial reaction kinetics and accelerate charge carrier transport for Li–S batteries.

MoO(3) nanostructures with different morphologies, such as helical nanosheets, crosslike nanoflowers, and nanobelts, have been synthesized on a large scale by an environmentally friendly chemical route. The evolution process from helical nanosheets to crosslike nanoflowers to nanobelts is observed for the first time. The influences of reaction time and the molar ratio of molybdenum and H(2)O(2) on the morphologies of MoO(3) nanostructures have been investigated. The synthetic process is environmentally friendly and may be extended to synthesize nanostructures of other metal (W, Ti, and Cr) oxides.

Single-crystal cerium hydroxide carbonate (Ce(OH)CO3) triangular microplates with the hexagonal phase have been successfully synthesized by a hydrothermal method at 150 degrees C using cerium nitrate (Ce(NO3)3.6H2O) as the cerium source, aqueous carbamide as both an alkaline and carbon source, and cetyltrimethylammonium bromide (CTAB) as a surfactant. Single-crystal ceria (CeO2) triangular microplates have been fabricated by a thermal decomposition-oxidation process at 650 degrees C for 7 h using single-crystal Ce(OH)CO3 microplates as the precursor. The shape of the Ce(OH)CO3 microplate was sustained after thermal decomposition-oxidation to CeO2. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FE-SEM), differential scanning calorimetric analysis (DSC), and thermogravimetric analysis (TG).

A novel high-voltage polymer electrolyte based on poly(vinylene carbonate-acrylonitrile) is successfully prepared for LiNi0.5Mn1.5O4 lithium batteries, which endows the high voltage batteries with significant improved performance.

As a next-generation electrochemical energy storage technology, rechargeable magnesium (Mg)-based batteries have attracted wide attention because they possess a high volumetric energy density, low safety concern, and abundant sources in the earth's crust. While a few reviews have summarized and discussed the advances in both cathode and anode materials, a comprehensive and profound review focusing on the material design strategies that are both representative of and peculiar to the performance improvement of rechargeable Mg-based batteries is rare. In this mini-review, all nine of the material design strategies and approaches to improve Mgion storage properties of cathode materials have been comprehensively examined from both internal and external aspects. Material design concepts are especially highlighted, focusing on designing "soft" anion-based materials, intercalating solvated or complex ions, expanding the interlayer of layered cathode materials, doping heteroatoms into crystal lattice, size tailoring, designing metastable-phase materials, and developing organic materials. To achieve a better anode, strategies based on the artificial interlayer design, efficient electrolyte screening, and alternative anodes exploration are also accumulated and analyzed. The strategy advances toward Mg−S and Mg−Se batteries are summarized. The advantages and disadvantages of allcollected material design strategies and approaches are critically discussed from practical application perspectives. This minireview is expected to provide a clear research clue on how to rationally improve the reliability and feasibility of rechargeable Mg-based batteries and give some insights for the future research of Mg-based batteries as well as other multivalent-ion battery chemistries.