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MoS 2 has been intensively studied as a promising anode material for high capacity lithium ion batteries (LIBs), which is strongly limited by its poor cycling stability and inferior rate performance. In this work, the strategy of interlayer spacing engineering is applied on MoS 2 to effectively expand the interlayer spacing from 0.62 nm to 0.98 nm, with the addition of ւ-cysteine during hydrothermal process. The cycling stability is significantly improved. The composites of interlayer expanded MoS 2 and graphene oxide are further treated by N plasma to effectively dope N into both reduce graphene oxide and MoS 2. The final product exhibits outstanding electrochemical performance as anode in LIBs, with high reversible capacity of 643 mA h·g−1 after 400 cycles at the rate of 500 mA g−1 and excellent rate capacity of 580 mA h·g−1 up to the rate of 2000 mA g−1. This work demonstrates that proper nanostructure engineering and electronic structure modification can make MoS 2 a promising electrode material in highly fast and stable energy storage applications. Image 1 • MoS 2 with enlarged interlayer spacing were synthesized. • Few-layered MoS 2 nanosheets grow vertically on GO sheets. • N plasma treatment is applied on GO/ISE-MoS 2 composites. • N has been uniformly doped into both rGO and MoS 2. • N-rGO/ISE-MoS 2 exhibits excellent reversible and rate capacity. [ABSTRACT FROM AUTHOR]

• The unique wounded CNTs were generated from the pyrolysis of the precursor without the addition of carbon sources. • The embedded Co 9 S 8 nanoparticle was obtained easily and required no further treatment or addition of metal sources. • This structure design strategy could be easily extended. • The Co 9 S 8 @NCNHP/S cathode exhibits the great electrochemical performance. [Display omitted] Lithium-sulfur (Li-S) battery is one of the most promising candidates for next-generation rechargeable batteries, while the volume expansion, severe shuttle effect, and sluggish reaction kinetics hinder its practical applications. Herein, a novel structure composed of Co 9 S 8 nanoparticles embedded in a N-doped carbon nanotube hollow polyhedron (Co 9 S 8 @NCNHP) is designed to address these issues. Co 9 S 8 nanoparticles can efficiently accelerate the kinetics of redox reaction and anchor the polysulfides, enhancing the electrochemical performance of cathodes. Furthermore, NCNHP can accommodate the huge volume expansion and block the diffusion of lithium polysulfides. Benefiting from this rational design, the Co 9 S 8 @NCNHP/S cathode exhibits a high initial discharge capacity of 1186 mAh·g−1 with a decay rate of 0.1% per cycle during 200 cycles at 0.2 C. An initial discharge capacity of 780 mAh·g−1 as well as a decay rate of 0.15% per cycle after 200 cycles can be obtained at a sulfur loading of 3.2 mg·cm−2. This strategy based on the combination of rational structure design and electrocatalysis could advance the cathode construction in Li-S batteries. [ABSTRACT FROM AUTHOR]

• A novel Ni 43 Mn 32 In 25 Heusler alloy film is deposited on Ni foam by PLD. • The activated NiMnIn/NF possesses overpotentials of 133.4 mV at a current density of –10 mA cm–2 for HER. • Electromagnet is used to realize the electrochemical measurement under in situ magnetic field. • Magnetic field promotes catalytic activity of NiMnIn/NF for HER. [Display omitted] Much effort has been devoted to developing novel electrodes of lower cost and higher efficiency to electrolyze water in scalable applications, which is mainly focused on 3d transition metals or oxides. In this work, Ni 43 Mn 32 In 25 (NiMnIn) Heusler alloy films with highly efficient hydrogen evolution reaction (HER) activity were deposited on porous Ni foam (NF) by pulsed laser deposition. With the synergetic contribution of constituent elements, the as-prepared NiMnIn films exhibited excellent performance with a low overpotential of 189.4 mV in the initial state and 133.4 mV after activation (at a current density of −10 mA cm−2) for HER in alkaline medium. Magnetic measurements have confirmed the ferromagnetic nature of NiMnIn films at room temperature, and the HER activity can be significantly improved by applying a magnetic field. The current density of NiMnIn/NF could be increased by 10% and 7% respectively, at a constant overpotential of 275 mV by applying a magnetic field of 8 kOe perpendicular and parallel to NF. This work suggests that Heusler alloys with various 3d transition metal constituents can be a potential efficient HER active electrode in water splitting, which has the magnetic field sensitivity for applications in magnetoelectrochemistry. [ABSTRACT FROM AUTHOR]

Petal-like graphene oxide-MoS 2 (GO-MoS 2) composites are prepared by the hydrothermal method. The structural characterizations confirm the metallic phase (1T) of MoS 2 sheets with a few layers, and the uniform distribution of graphene oxide (GO) and MoS 2. However, the functional groups on the surface of GO and the intrinsic low conductivity of MoS 2 lead to the poor electrochemical performance of GO-MoS 2 in lithium ion batteries. N-doped GO-MoS 2 (N-GO-MoS 2) composites are prepared by N plasma treatment on GO-MoS 2 composites at room temperature. N is clearly confirmed to be doped into both graphene oxide and MoS 2 uniformly, and MoS 2 changes to semiconducting phase (2H). In lithium ion batteries, it is found that the initial capacity increases from 561.4 mAh g−1 for GO-MoS 2 to 726.9 mAh g−1 for N-GO-MoS 2 at 1 C. After 100 cycles, N-GO-MoS 2 still exhibits capacity of 592.7 mAh g−1 (1.34 mAh g−1 loss per cycles and 81.5% capacity retention rate), which is much better than that of GO-MoS 2 (only 31.6 mAh g−1 after 100 cycles). The significantly improved high-rate cycling electrochemical performance for N-GO-MoS 2 can be attributed to the improved stability of MoS 2 by the phase transition from 1T to 2H, the enhanced electron transportation by the reduction of graphene oxide to graphene and the simultaneous N doping in MoS 2 and graphene oxide. Image 1 • N plasma treatment is applied on graphene oxide (GO)-MoS 2 composites (N-GO-MoS 2). • N has been successfully doped into both GO and MoS 2. • The structure of MoS 2 transforms from the metallic phase (1T) to semiconducting phase (2H). • The electrochemical performance of N-GO-MoS 2 anode has been significantly improved due to better electronic conductivity. [ABSTRACT FROM AUTHOR]