The low electrochemical utilization of S and fast capacity fading can be effectively diminished by immobilizing sulfur in porous carbon via the interaction of a small amount of selenium in S-rich S1−xSex/C (x ≤ 0.1) composites.

Sb nanoparticles with a size of 55 nm are fabricated via the reduction of SbCl3 by metallic Al in the molten salt of SbCl3 at 80 °C. In situ XRD patterns and ex situ Raman spectra show that the potassium storage mechanism is an alloying-type with the formation of a cubic K3Sb phase when fully potassiated and an amorphous phase when fully depotassiated. As an anode for potassium-ion batteries, Sb nanoparticles coated with graphene could deliver a reversible capacity of 381 mA h g-1 at 100 mA g-1, and maintain a capacity of 210 mA h g-1 at 500 mA g-1 for 200 cycles.

A deep reduction and partial oxidation strategy to convert low-cost SiO2 into mesoporous Si anode with the yield higher than 90% is provided. This strategy has advantage in efficient mesoporous silicon production and in situ formation of several nanometers SiO2 layer on the surface of silicon particles. Thus, the resulted silicon anode provides extremely high reversible capacity of 1772 mAh g(-1), superior cycling stability with more than 873 mAh g(-1) at 1.8 A g(-1) after 1400 cycles (corresponding to the capacity decay rate of 0.035% per cycle), and good rate capability (∼710 mAh g(-1) at 18A g(-1)). These promising results suggest that such strategy for mesoporous Si anode can be potentially commercialized for high energy Li-ion batteries.

For lithium‐selenium batteries, commercial applications are hindered by the inferior electrical conductivity of selenium and the low utilization ratio of the active selenium. Here, we report a new baked‐in‐salt approach to enable Se to better infiltrate into metal‐complex‐derived porous carbon (Se/MnMC‐B). The approach uses the confined, narrow space that is sandwiched between two compact NaCl solid disks, thus avoiding the need for protection with argon or a vacuum environment during processing. The electrochemical properties for both lithium and sodium storage of our Se/MnMC‐B cathode were found to be outstanding. For lithium storage, the Se/MnMC‐B cathode (with 72% selenium loading) exhibited a capacity of 580 mA h g−1 after 1000 cycles at 1 C, and an excellent rate capability was achieved at 20 C and 510 mA h g−1. For sodium storage, a specific capacity of 535 mA h g−1 was achieved at 0.1 C after 150 cycles. These results demonstrate the potential of this approach as a new effective general synthesis method for confining other low melting point materials into a porous carbon matrix.

The common sulfur/carbon (S/C) composite cathodes in lithium sulfur batteries suffer gradual capacity fading over long-term cycling incurred by the poor physical confinement of sulfur in a nonpolar carbon host. In this work, these issues are significantly relieved by introducing polar SnO2 or SnS2 species into the S/C composite. SnO2- or SnS2-stabilized sulfur in porous carbon composites (SnO2/S/C and SnS2/S/C) have been obtained through a baked-in-salt or sealed-in-vessel approach at 245 °C, starting from metallic tin (mp 231.89 °C), excess sulfur, and porous carbon. Both of the in situ-formed SnO2 and SnS2 in the two composites could ensure chemical interaction with lithium polysulfide (LiPS) intermediates proven by theoretical calculation. Compared to SnO2/S/C, the SnS2/S/C sample affords a more appropriate binding effect and shows lower charge transfer resistance, which is important for the efficient redox reaction of the adsorbed LiPS intermediates during cycling. When used as cathodes for Li-S batteries, the SnS2/S/C composite with sulfur loading of 78 wt % exhibits superior electrochemical performance. It delivers reversible capacities of 780 mAh g(-1) after 300 cycles at 0.5 C. When further coupled with a Ge/C anode, the full cell also shows good cycling stability and efficiency.

Iron oxide (Fe3O4) nanowires encapsulated in carbon microtubes (defined as “CIOs”) with a diameter range of 150−1500 nm, and lengths up to 6 um were obtained by pyrolyzing an ethanol/ferrocene mixture in an autoclave at 600 °C. The inner Fe3O4 nanowires (defined as “IOs”) are single crystalline with a diameter range of 55−750 nm. Magnetic hysteresis loop measurements show that the CIOs display ferromagnetic properties at room temperature. In addition, carbon microtubes (CMTs) were obtained after the inside IOs were dissolved by aqueous HCl acid.

Highly uniform urchin-like nanostructures (in the structures, nanoneedles or nanobelts grow radially from the core particles) of NiS (millerite) were successfully prepared by a solvothermal synthetic route using Ni(Ac) 2 ·6H 2 O and dithizone as reagents and ethylenediamine as solvent in the temperature range of 220−240°C. The prepared nickel sulfides with urchin-like 3D architectures were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron micro-

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