High-quality Prussian blue crystals with a small number of vacancies and a low water content are obtained by employing Na sub(4)Fe(CN) sub(6) as the single iron-source precursor. The high-quality ...Prussian blue shows high specific capacity and remarkable cycling stability as the cathode material for Na-ion batteries because of its excellent ion storage capability and impressive structure stability.
Room‐temperature sodium‐ion batteries (SIBs) have shown great promise in grid‐scale energy storage, portable electronics, and electric vehicles because of the abundance of low‐cost sodium. ...Sodium‐based layered oxides with a P2‐type layered framework have been considered as one of the most promising cathode materials for SIBs. However, they suffer from the undesired P2–O2 phase transition, which leads to rapid capacity decay and limited reversible capacities. Herein, we show that this problem can be significantly mitigated by substituting some of the nickel ions with magnesium to obtain Na0.67Mn0.67Ni0.33−xMgxO2 (0≤x≤0.33). Both the reversible capacity and the capacity retention of the P2‐type cathode material were remarkably improved as the P2–O2 phase transition was thus suppressed during cycling. This strategy might also be applicable to the modulation of the physical and chemical properties of layered oxides and provides new insight into the rational design of high‐capacity and highly stable cathode materials for SIBs.
The P2–O2 phase transition in P2‐Na0.67Mn0.67Ni0.33−xMgxO2 can be effectively suppressed by substituting some of the nickel ions with magnesium. Both the reversible capacity and the capacity retention of this cathode material were thus remarkably improved, and the various phases were characterized by scanning tunneling electron microscopy with atomic resolution.
A subzero‐temperature cathode material is obtained by nucleating cubic prussian blue crystals at inhomogeneities in carbon nanotubes. Due to fast ionic/electronic transport kinetics even at −25 °C, ...the cathode shows an outstanding low‐temperature performance in terms of specific energy, high‐rate capability, and cycle life, providing a practical sodium‐ion battery powering an electric vehicle in frigid regions.
The authors conduct a meta-analysis on the effect of electronic word of mouth on sales by examining 51 studies (involving 339 volume and 271 valence elasticities) and primary data collected on ...product characteristics (durability, trialability, and usage condition), industry characteristics (industry growth and competition), and platform characteristics (expertise and trustworthiness). Their analysis reveals that electronic word-of-mouth volume (valence) elasticity is .236 (.417). More importantly, the findings show that volume and valence elasticities are higher for privately consumed, low-trialability products that operate in less competitive industries and whose reviews are carried on independent review sites. Furthermore, volume elasticities are higher for durable goods and for reviews on specialized review sites, whereas valence elasticities are greater for community-based sites. Drawing on the results, they discuss several implications for managers and researchers and explain why valence elasticities are often found to be insignificant. Finally, they propose numerous directions for future research in the area on the basis of their findings.
The fabrication of silicon anode materials using biomass resources enables the effective utilization of subsidiary agricultural products in battery industries, despite the electrochemical ...performances of these as-synthesized silicon materials still need improvements. Using rice husk (RH) as silicon source, here we report for the first time the fabrication of silicon/nitrogen-doped carbon/carbon nanotube (SNCC) nano/micro-hierarchical structured spheres through a facile electrospray approach. The unique hierarchical hybrid structure of the composite spheres, in which the silicon nanoparticles are homogenously encapsulated in the highly conductive, porous carbon matrix built by carbon nanotubes and nitrogen-doped carbon, contributes to fast electronic transport and prevents silicon from pulverization possessing good structure stability upon the synergistic lithiation/delithiation of the components. These SNCC spheres could deliver a high reversible specific capacity of 1380mAhg−1 at a current density of 0.5Ag−1, and still maintain 1031mAhg−1 after 100 cycles. The low cost RH-derived silicon composites synthesized by a facile, scalable synthetic method turn out to be promising for the next-generation rechargeable lithium-ion batteries.
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•Low-cost rice husks are utilized to fabricate Si-based anode material for Li-ion batteries.•Using electrospray method to fabricate homogeneous Si/N-doped carbon/CNT nano/micro-hierarchical structured spheres.•The unique hierarchical hybrid structure of the composite contributes to an excellent electrochemical performance.
Driven by an increasing demand on storage devices with higher energy outputs and better safety, solid-state lithium metal batteries have shown their potential to replace the traditional liquid-based ...Li-ion batteries and power the future storage market. In this Perspective, we will show our views on improving this emerging battery system by nanoscience. Discussions will be placed, from both scientific and engineering points of view, on the fundamentals and problems of the battery and its key components. The corresponding “nano” strategies will also be addressed, as well as recent progress in related fields including materials synthesis, battery design, and characterization techniques. With these efforts, we want to provide insights on rational design of the solid-state Li metal battery for optimized performance.
Indium-oxide (In2O3) nanobelts coated by a 5-nm-thick carbon layer provide an enhanced photocatalytic reduction of CO2 to CO and CH4, yielding CO and CH4 evolution rates of 126.6 and 27.9 μmol h–1, ...respectively, with water as reductant and Pt as co-catalyst. The carbon coat promotes the absorption of visible light, improves the separation of photoinduced electron–hole pairs, increases the chemisorption of CO2, makes more protons from water splitting participate in CO2 reduction, and thereby facilitates the photocatalytic reduction of CO2 to CO and CH4.
Silicon has attracted much attention as a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity and rich resource abundance. However, the practical battery ...use of Si is challenged by its low conductivity and drastic volume variation during the Li uptake/release process. Tremendous efforts have been made on shrinking the particle size of Si into nanoscale so that the volume variation could be accommodated. However, the bare nano-Si material would still pulverize upon (de)lithiation. Moreover, it shows an excessive surface area to invite unlimited growth of solid electrolyte interface that hinders the transportation of charge carriers, and an increased interparticle resistance. As a result, the Si nanoparticles gradually lose their electrical contact during the cycling process, which accounts for poor thermodynamic stability and sluggish kinetics of the anode reaction versus Li. To address these problems and improve the Li storage performance of nano-Si anode, proper structural design should be applied on the Si anode. In this perspective, we will briefly review some strategies for improving the electrochemistry versus Li of nano-Si materials and their derivatives, and show opinions on the optimal design of nanostructured Si anode for advanced LIBs.
Nickel ferricyanide is demonstrated as a zero-strain insertion cathode material for room-temperature sodium-ion batteries that can effectively accommodate volume variation during Na super(+) ...insertion/extraction. Given its highly stable structure, nickel ferricyanide shows impressive cycling performance and Coulombic efficiency.
A palladium catalyzed reductive aminocarbonylation of benzylic ammonium triflates with nitroarenes for the synthesis of phenylacetamides was developed. Using Pd(acac)2/DPPF catalyst system, a range ...of different substituted phenylacetamides were prepared in moderate to good yields from benzylic ammonium triflates and nitroarenes through Csp3−N bond cleavage. A variety of alkyl, aryl, and halide substituents on both substrates can be used, and many useful functional groups can be tolerated.
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