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Lithium-ion battery (LIBs) applications using antimony (Sb) based anodes with high specific capacity and suitable operating voltage have showed tremendous potential. However, the large volume variation during electrochemical cycling limits their application. In this paper, M-Sb (M=Co, Ni) nanoparticles embedded in nitrogen doped carbon nanofibers have been prepared by an electrospinning method, 3D interconnected M-Sb@CN (NiSb@CN and Sb/CoSb 2 @CN) fiber composites are obtained finally. M-Sb nanoparticles are uniformly distributed in N-doped carbon nanofibers, which can prevent their direct exposure to the electrolyte. Compared with bare Sb-M and Sb-C binary electrodes, the M-Sb-C three-component composite electrodes show smaller volume change and stronger charge transport ability. The introduction of the transition metal (Co, Ni) not only serves as buffer substrate for volume change, but also regulates the properties of carbon fibers as a catalyst. High reversible capacities of 647.4 and 620.2 mA h g−1 of NiSb@CN and Sb/CoSb 2 @CN fiber composites can be maintained after 600 cycles at a current rate of 500 mA g−1. First principles calculation demonstrates that N-doping and the incorporation of transition metal M have favorable effect on the improved Li binding energy, offering a possibility for the material design of the high-performance LIBs. [ABSTRACT FROM AUTHOR]

Highly-crystallized cubic cattierite CoS 2 pyramids were deposited on Ti foil via a simple hydrothermal method using CoCl 2 and thiourea as precursors. Scanning electron microscopy (SEM) characterization revealed the morphology evolution from ramdom nanoparticles to micro-pyramids with well defined facets. These CoS 2 pyramids were applied as electrocatalysts for hydorgen evolution reaction (HER) and showed very different acidic HER performance. The sample prepared at 15 h reaction time showed the best performance with an onset overpotential as low as 81 mV and a Tafel slope of ∼72 mV/dec. The activity was kept almost 89% even after working for 30,000 seconds. Further study showed that these CoS 2 pyramids also functioned well in neutral (1.0 M potassium phosphate buffer solution, pH = 7.00) and alkaline (1.0 M KOH solution, pH = 13.57) conditions. The cubic cattierite-type CoS 2 can work as a novel HER electrocatalyst over the wide pH range from 0 to 14, combined with its easy-synthesis, low-cost and high stability, which can potentially serve as a ready-to-go HER catalyst for practical utilization. [ABSTRACT FROM AUTHOR]