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A carbon layer usually covers the outside of SnS/MoS2 nanosheets produced by a traditional C-layer cladding process, resulting in a material with a lower specific surface area and fewer active sites. Therefore, it is difficult for these as-obtained SnS and MoS2 materials to be directly employed as electrode materials. There is a great need to develop a new C-layer coating process that can effectively coat active materials and simultaneously increase the specific surface area. In this study, novel SnS@C/MoS2 nanotubes were designed and synthesized by a self-sacrificing template method (SSTM). Specifically, MoO3 nanoribbons were first coated with Sn to produce Sn-MOF, and SnS@C/MoS2 nanotubes with a particular nanosheet architecture preserved were achieved via an elegant SSTM vulcanization strategy. This SSTM preparation method not only retains the nanosheet microstructure of the surface but also leaves a thin layer of amorphous carbon on the surface, which greatly improves the conductivity and effectively improves the cycling stability. In addition to above-mentioned advantages, there is a synergistic effect between the various components of the SnS@C/MoS2 nanotubes, which has a positive effect on the electrochemical performance. When used as the anode of a lithium-ion battery (LIB), the SnS@C/MoS2 composite can maintain a specific discharge capacity of 970.9 mAh g−1 after 500 cycles at a current density of 1 A g−1, and a specific discharge capacity of 778.1 mAh g−1 even after 1000 cycles at a current density of 2 A g−1. This method provides a reference for the synthesis of other nanostructured materials. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) have been extensively studied due to their porous structures and large specific surface areas. Its unique combination of central metal and organic ligand has become a common precursor for the synthesis of metal phosphides, selenides, oxides, and sulfides. However, the carbonaceous structure derived from some MOF materials is still not enough to perfectly alleviate the negative impact of the volume change of metal sulfides. Herein, bimetallic MOF (Zn‐Co‐ZIF) is used as a precursor, coated with dopamine hydrochloride, and then calcined and gas‐phase vulcanized to prepare ZnS/CoS2‐C@NC with a double‐carbon‐layer core–shell structure. The existence of the two carbonaceous structures can not only improve the electron transport ability, but also play an important role in alleviating the volume expansion caused by metal sulfides during repeated charging and discharging. Due to its stable carbon layer structure, ZnS/CoS2‐C@NC has a higher specific capacity (1175.4 mAh g−1 in lithium‐ion batteries (LIBs) and 430.9 mAh g−1 in sodium‐ion batteries after 100 cycles at a current density of 0.2 A g−1 respectively) and excellent rate capability (338.2 mAh g−1 specific capacity maintained after 2000 cycles at a current density of 5 A g−1 in LIBs). [ABSTRACT FROM AUTHOR]

Metal sulfides, one kind of electrode material with very high theoretical capacity, have been widely studied for use in lithium and sodium ion batteries. However, there are some problems hindering their applications in electrodes, such as low conductivity and volume expansion. The MOF introduces metals with different coordination strengths into an existing MOF structure, which improves the performance of the electrode to a certain extent. In this paper, Fe/Zn bimetallic MOF rod-like superstructure was prepared based on Ostwald theory. Accompanied by sulfuration, the MOF was effectively combined with MoS2 and GO, and the objective materials Fe7S8-C/ZnS-C@MoS2/rGO composites were successfully prepared. The MOF material provides a good frame and an efficient electron transport path, while the robust rGO wall effectively inhibits the pulverization of materials during the lithium/sodium intercalation/escalation courses. This particular material exhibited excellent cycling and rate capability performance when used in Li/Na-ion batteries. When used in Li-batteries, the electrode material delivered a specific capacity of 1598.3 mA h g−1 at 0.1 A g−1 and remained at 1196.7 mA h g−1 even after about 100 cycles and further exhibited a specific capacity of 368.68 mA h g−1 at the current rate of 5 A g−1 even after 1000 cycles, respectively. As for sodium batteries, these electrode materials exhibited an initial reversible capacity of 1053.6 mA h g−1 at 0.1 A g−1 and the reversible capacity was still as high as 592.2 mA h g−1 after 200 cycles. It is perhaps that this composite material with its particular architecture and composition is greatly beneficial for electron transfer and Li/Na ion diffusion. In the repeated physicochemical/nutrifying process, the appropriate distance between adjacent MOFs is of great help in preventing volume changes and thus improving the electrochemical performance. [ABSTRACT FROM AUTHOR]

Uniform Sn/C hybrid core/shell nanocomposites were synthesized by a combination of electrospinning and subsequent thermal treatment in a reducing atmosphere. The particular three-dimensional architecture, consisting of a Sn@C nanoparticle core and porous hollow carbon nanofiber shell, is characterized by many micro/nanochannels, enhanced mechanical support from the three-dimensional hollow carbon shell, and the abundant porous carbon matrix. The as-prepared Sn/C core/shell nanomaterials exhibit excellent electrochemical performance. They display a reversible capacity of 546.7 mAhg −1 up to 100 cycles at the current density of 40 mAg −1 and good rate capability of 181.8 mAhg −1 at 4000 mAg −1 . These results indicate that the composite could be a promising anode candidate for lithium ion batteries. [ABSTRACT FROM AUTHOR]

Abstract: Novel MnOx@Carbon hybrid nanowires were successfully synthesized by the combination of a hydrothermal process and a simple PVP (polyvinylpyrrolidone) – solution-soaking method followed by a subsequent carbonization treatment. The nanostructures exhibit the unique feature of having nanocrystalline manganese oxide particle encapsulated inside and an amorphous carbon layer coating the outside. The unique porous characteristics with many meso/micro-pores, and further the highly conductive carbon matrix would lead to the excellent electrochemical performance of the MnOx@Carbon nanowire electrode. The MnOx@Carbon hybrid nanowires exhibit a high initial reversible capacity of 824.4 mAhg−1, a reversible capacity of approximately 541 mAhg−1 after 54 cycles, and excellent cycling stability and rate capability with specific capacity of 298.24 mAhg−1 when cycled at the current density of 1000 mAg−1, which indicates that the composite is a promising anode candidate for Li-ion batteries. [Copyright &y& Elsevier]

Abstract: Very large area, uniform Li4Ti5O12/carbon composite nanowebs consisting of interconnected nanofibers were synthesized by a simple method based on thermal pyrolysis and oxidation of a composite of electrospun lithium–titanium/polyacrylonitrile nanowebs in argon atmosphere. This novel composite is characterized by the encapsulation of highly uniform nanoscale Li4Ti5O12 crystals in the porous cotton-like carbon matrix. This unique structure, consisting of ultra-small crystals in carbon core/shell architecture, is also characterized by high porosity, with many nanopores and mesopores in the composite, and this, together with the high conductive carbon matrix, would facilitate the excellent electrochemical performance of Li4Ti5O12/carbon composite nanoweb electrode. The Li4Ti5O12/carbon hybrid nanoweb electrodes display a reversible capacity of approximately 160.8 mAhg−1 at a current density of 30 mAg−1 and excellent cycling stability. The Li4Ti5O12/carbon hybrid nanoweb electrodes also exhibit excellent rate performance, delivering a discharge capacity of over 87 mAhg−1 at a current density of 3000 mAg−1. These results indicate that the composite is a promising anode candidate for lithium ion batteries. [Copyright &y& Elsevier]

Abstract: Novel TiO2(B)@anatase hybrid nanowires with a bicrystalline structure consisting of TiO2(B) core and anatase shell exhibit superior Li ion storage capacities, cycling stability and rate capability. Owing to the excellent electrochemical performance, TiO2(B)@anatase hybrid nanowires could be promising anode materials for lithium ion batteries. [Copyright &y& Elsevier]

Abstract: Under optimized synthesis conditions, very large area uniform SnO2 nanofibers consisting of orderly bonded nanoparticles have been obtained for the first time by thermal pyrolysis and oxidization of electrospun tin(II)2-ethylhexanoate/polyacrylonitrile (PAN) polymer nanofibers in air. The structure and morphology were elaborated by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The SnO2 nanofibers delivered a reversible capacity of 446mAhg−1 after 50 cycles at the 100mAg−1 rate and excellent rate capability of 477.7mAhg−1 at 10.0C. Owing to the improved electrochemical performance, this electrospun SnO2 nanofiber could be one of the most promising candidate anode materials for the lithium-ion battery. [Copyright &y& Elsevier]