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A concentrated dual-salts LiFSI-LiNO 3 /DOL electrolyte was prepared by using LiNO 3 as the inhibitor. The LiF-Li 2 O-oligomers composite SEI layers can efficiently accommodate the rapid plating/stripping of Li metal. A high average Coulombic efficiency of 99.14% was achieved under a large current density of 8.0 mA cm−2. [Display omitted] Developing a high-rate Li metal anode with superior reversibility is a prerequisite for fast-charging Li metal batteries. However, the build-up of large concentration gradients under high current density leads to inhomogeneous Li deposition and unstable passivation layers of Li metal, resulting in lower Coulombic efficiency. Here we report a concentrated dual-salts LiFSI-LiNO 3 /DOL electrolyte to improve the high-rate performance of Li metal anode. Sufficient Li salts help passivate the fresh Li deposition quickly. Further, DOL contributes to the formation of flexible organic layers that can accommodate the rapid volume change of Li metal upon cycling. Li metal in the electrolyte remains stable over 240 cycles with the average Coulombic efficiency of 99.14% under a high current density of 8.0 mA cm−2. [ABSTRACT FROM AUTHOR]

Here we report an environmentally friendly, one-pot strategy toward preparation of nickel nanoparticle-decorated reduced graphene-oxide (Ni-RGO) nanostructures, by employing Ni(AC) 2 as nickel source and ethylene glycol as both solvent and reducing agent via a facile microwave irradiation heating approach. The results show that Ni nanoparticles with an average diameter of around 40 nm are homogeneously anchored onto the surface of RGO sheets. As compared to the pure Ni nanoparticles and RGO sheets, Ni-RGO composites with over 64 wt% loading of Ni nanoparticles possess superior catalytic activities and selectivity toward the reduction of 4-nitrophenol. The corresponding kinetic reaction rate constant (defined as κ ) is even four-fold compared to pure Ni nanoparticles. Such promising composites show great potential for friendly treatment of industrial waste containing nitrophenol in a simple, sustainable and green way. [ABSTRACT FROM AUTHOR]

Li-O 2 battery is the leading next-generation battery system, which is known for its extremely high theoretic specific energy. However, the Li metal used in Li-O 2 batteries suffers from low Li utilization and safety hazards. In this work, as an alternative to Li anode, Li 21 Si 5 powders, which are synthesized by an easy mechanical process, are incorporated into a Li-ion oxygen battery. The electrochemical property of the prepared battery and its cycling stability are investigated. Without electrochemical prelithiation, the pursuit of Li-Si alloy anodes in this study provides an easy and scalable strategy for preparing Li-ion oxygen batteries. [ABSTRACT FROM AUTHOR]

We confirmed the existence of LiO 2 by electrochemical quartz crystal microbalance (EQCM) in TEGDME based Li-O 2 batteries. Our results indicated that Li 2 O 2 is generated through stepwise electrochemical reactions rather than disproportionation. We report for the first time that the formed Li 2 O 2 oxidizes to LiO 2 at relative negative potential and O 2 at positive potential respectively. Our conclusions were based on both experimental observations and quantitative analysis. This may enlighten us to reconsider the Li-O 2 batteries mechanisms in a quantitative way. [ABSTRACT FROM AUTHOR]

A polyaniline/graphene composite with covalently-bond is synthesized by a novel approach. In this way, graphene oxide is functionalized firstly by introducing amine groups onto the surface with the reduction of graphene oxide in the process and then served as the anchor sites for the growth of polyaniline (PANI) via in-situ polymerization. The composite material is characterized by electron microscopy, the resonant Raman spectra, X-ray diffraction, transform infrared spectroscopy and X-ray photoelectron spectroscopy. The electrochemical properties of the composite are measured by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charging/discharging. With the functionalization process, the graphene/polyaniline composite electrode exhibits remarkably enhanced electrochemical performance with specific capacitance of 489 F g −1 at 0.5 A g −1 , which is superior to those of its individual components. The outstanding electrochemical performance of the hybrid can be attributed to its covalently synergistic effect between graphene and polyaniline, suggesting promising potentials for supercapacitors. [ABSTRACT FROM AUTHOR]

The NASICON structure of Na 3 V 2 (PO 4) 2 F 3 (NVPF) separates the valence electrons between the polyanion group and V and regulates the redox coupling energy. As a result, NVPF exhibits a high operating voltage in sodium-ion batteries. However, NVPF cathode material has poor specific capacity and low-rate performance. It is necessary to improve the electrochemical performance by increasing the electronic conductivity and accelerating the ion diffusion rate. Through morphology control, more active sites and ion channels can be provided to enhance rate performance and cycle stability. However, there are few reviews on how to control the morphology of NVPF. Therefore, this paper starts with the factors affecting the morphology of NVPF. The effects of pH value, surfactant, and external additives on its morphology were systematically summarized. On this basis, reasonable strategies, including morphology design, preparation method, structure control, surface modification, and defect engineering, are summarized. This paper provides theoretical support for the development of high-voltage NVPF. It provides inspiration for creating NVPF cathode materials with high specific capacity and high cycle performance. • The effects of various factors on the morphology of Na 3 V 2 (PO 4) 2 F 3 were systematically summarized. • The electrochemical properties of Na 3 V 2 (PO 4) 2 F 3 coated with different carbon sources were summarized. • The low-pressure platform caused by fluorine loss and its fluorine supplement measures are explained. • The effects of binders and electrolyte additives on Na 3 V 2 (PO 4) 2 F 3. [ABSTRACT FROM AUTHOR]