The calcium-ion-storage mechanism of VOPO4·2H2O is studied by in situ XRD and in situ Raman for the first time.

Routine electrolyte additives are not effective enough for uniform zinc (Zn) deposition, because they are hard to proactively guide atomic-level Zn deposition. Here, based on underpotential deposition (UPD), we propose an "escort effect" of electrolyte additives for uniform Zn deposition at the atomic level. With nickel ion (Ni 2 + ) additives, we found that metallic Ni deposits preferentially and triggers the UPD of Zn on Ni. This facilitates firm nucleation and uniform growth of Zn while suppressing side reactions. Besides, Ni dissolves back into the electrolyte after Zn stripping with no influence on interfacial charge transfer resistance. Consequently, the optimized cell operates for over 900 h at 1 mA cm À 2 (more than 4 times longer than the blank one). Moreover, the universality of "escort effect" is identified by using Cr 3 + and Co 2 + additives. This work would inspire a wide range of atomic-level principles by controlling interfacial electrochemistry for various metal batteries.

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The uncontrollable formation of Li dendrites has become the biggest obstacle to the practical application of Li metal anode in high-energy rechargeable Li batteries. Herein, a unique LiF interlayer woven by millimeter-level, single-crystal and serrated LiF nanofibers was designed to enable dendrite-free and highly efficient Li metal deposition. This high-conductivity LiF interlayer can increase the Li+ transference number and induce the formation of ‘LiF-NFs-rich’ SEI. In the ‘LiF-NFs-rich’ SEI, the ultralong LiF nanofibers provide a continuously interfacial Li+ transport path. Moreover, the formed Li-LiF interface between Li metal and SEI film renders the low Li nucleation and high Li+ migration energy barriers, leading to the uniform Li plating and stripping processes. As a result, steady charge-discharge in a Li//Li symmetric cell for 1600 h under 4 mAh cm−2, and 400 stable cycles under a high area capacity of 5.65 mAh cm−2 in a high-loading Li//rGO-S cell at 17.9 mA cm−2 could be achieved. The free-standing LiF-NFs interlayer exhibits superior advantages for commercial Li batteries and displays significant potential for expanding the applications in solid Li batteries.

Bismuth‐based materials have been recognized as promising catalysts for the electrocatalytic CO2 reduction reaction (ECO2RR). However, they show poor selectivity due to competing hydrogen evolution reaction (HER). In this study, we have developed an edge defect modulation strategy for Bi by coordinating the edge defects of bismuth (Bi) with sulfur, to promote ECO2RR selectivity and inhibit the competing HER. The prepared catalysts demonstrate excellent product selectivity, with a high HCOO− Faraday efficiency of ≈95 % and an HCOO− partial current of ≈250 mA cm−2 under alkaline electrolytes. Density function theory calculations reveal that sulfur tends to bind to the Bi edge defects, reducing the coordination‐unsaturated Bi sites (*H adsorption sites), and regulating the charge states of neighboring Bi sites to improve *OCHO adsorption. This work deepens our understanding of ECO2RR mechanism on bismuth‐based catalysts, guiding for the design of advanced ECO2RR catalysts.

Molybdenum trioxide has served as a promising cathode material of rechargeable magnesium batteries (RMBs), because of its rich valence states and high theoretical capacity; yet, it still suffers from sluggish (de)­intercalation kinetics and inreversible structure change for highly polarized Mg2+ in the interlayer and intralayer of structure. Herein, F– substitutional and H+ interstitial doping is proposed for α-MoO3 materials (denoted HMoOF) by the intralayer/interlayer engineering strategy to boost the performance of RMBs. F– substitutional doping generates molybdenum vacancies along the Mo–O-□ or Mo–F-□ configurations (where □ represents the cationic vacancy) for unlocking the inactive basal plane of the layered crystal structure, and it further accelerates Mg2+ diffusion along the b-axis. Interstitial-doped H+ can expand interlayer spacing for reducing Mg2+ energy barrier along the ac plane and serve as a “pillar” to stabilize the interlayer structure. Moreover, anion and cation dual doping trigger shallow impurity levels (acceptors levels and donor levels), which helps to easily acquire the electrons from the valence band and donate the electrons to the conduction band. Consequently, the HMoOF electrode exhibits a high reversible capacity (241 mA h g–1 at 0.1 A g–1), an excellent rate capability (137.4 mAh g–1 at 2 A g–1), and a long cycling stability (capacity retention of 98% after 800 cycles at 1 A g–1) in RMBs. This work affords meaningful insights in layered materials for developing high-kinetics and long-life RMBs.