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Practical application of high-energy-density lithium (Li) metal batteries is hindered by instability of the solid electrolyte interphase (SEI) that grows as a passivation layer on the anode surface. Attempts to address SEI degradation often involve a rational modification of its composition, through the introduction of appropriate electrolytic additives. Notably, amalgamation of a fluorine (F) source and a nitrate (NO3−) source as additives for growing a fluorinated-nitrided SEI in situ has been previously reported to enhance battery performance and longevity. However, the intrinsic structure and properties of such mixed SEI phases remain poorly understood. Herein, using atomistic simulations, we present the synergetic chemistry of nitrate-based additives with lithium fluoride (LiF), with potentially transformative impact on SEI performance. Our studies demonstrate that spontaneous Li-induced decomposition of NO3− leads to dispersion of lithiophilic impurities with a stabilizing influence on desirable amorphous SEI phases. Furthermore, detailed analyses showcase mixed LiF(NO3) phases to be capable of being electronically insulating super Li-ionic conductors with exceptional ductility over a wide lithiation window. Such atomic level findings may be essential for in situ SEI design strategies that can help improve interfacial stability in rechargeable batteries. [ABSTRACT FROM AUTHOR]

Graphite anodes offer low volumetric capacity in lithium‐ion batteries. By contrast, tellurene is expected to alloy with alkali metals with high volumetric capacity (≈2620 mAh cm−3), but to date there is no detailed study on its alloying behavior. In this work, the alloying response of a range of alkali metals (A = Li, Na, or K) with few‐layer Te is investigated. In situ transmission electron microscopy and density functional theory both indicate that Te alloys with alkali metals forming A2Te. However, the crystalline order of alloyed products varies significantly from single‐crystal (for Li2Te) to polycrystalline (for Na2Te and K2Te). Typical alloying materials lose their crystallinity when reacted with Li—the ability of Te to retain its crystallinity is therefore surprising. Simulations reveal that compared to Na or K, the migration of Li is highly "isotropic" in Te, enabling its crystallinity to be preserved. Such isotropic Li transport is made possible by Te's peculiar structure comprising chiral‐chains bound by van der Waals forces. While alloying with Na and K show poor performance, with Li, Te exhibits a stable volumetric capacity of ≈700 mAh cm−3, which is about twice the practical capacity of commercial graphite. [ABSTRACT FROM AUTHOR]

Abstract: Rhenium disulfide (ReS2) differs fundamentally from other group‐VI transition metal dichalcogenides (TMDs) due to its low structural symmetry, which results in its optical and electrical anisotropy. Although vertical growth is observed in some TMDs under special growth conditions, vertical growth in ReS2 is very different in that it is highly spontaneous and substrate‐independent. In this study, the mechanism that underpins the thermodynamically favorable vertical growth mode of ReS2 is uncovered. It is found that the governing mechanism for ReS2 growth involves two distinct stages. In the first stage, ReS2 grows parallel to the growth substrate, consistent with conventional TMD growth. However, subsequent vertical growth is nucleated at points on the lattice where Re atoms are “pinched” together. At such sites, an additional Re atom binds with the cluster of pinched Re atoms, leaving an under‐coordinated S atom protruding out of the ReS2 plane. This under‐coordinated S is “reactive” and binds to free Re and S atoms, initiating growth in a direction perpendicular to the ReS2 surface. The utility of such vertical ReS2 arrays in applications where high surface‐to‐volume ratio and electric‐field enhancement are essential, such as surface enhanced Raman spectroscopy, field emission, and solar‐based disinfection of bacteria, is demonstrated. [ABSTRACT FROM AUTHOR]

The adsorption and activation of CO 2 molecules on the surface of photocatalysts are critical steps to realize efficient solar energy-induced CO 2 conversion to valuable chemicals. In this work, a defect engineering approach of a high-valence cation Nb-doping into TiO 2 was developed, which effectively enhanced the adsorption and activation of CO 2 molecules on the Nb-doped TiO 2 surface. A highly ordered Nb-doped TiO 2 nanotube array was prepared by anodization of the Ti-Nb alloy foil and subsequent annealing at 550 °C in air for 2 h for its crystallization. Our sample showed a superior photocatalytic CO 2 reduction performance under simulated solar illumination. The main CO 2 reduction product was a higher-energy compound of acetaldehyde, which could be easily transported and stored and used to produce various key chemicals as intermediates. The acetaldehyde production rate was over ∼500 μmol·g -1 ·h -1 with good stability for repeated long-time uses, and it also demonstrated a superior product selectivity to acetaldehyde of over 99%. Our work reveals that the Nb-doped TiO 2 nanotube array could be a promising candidate with high efficiency and good product selectivity for the photocatalytic CO 2 reduction with solar energy.