Effect of porous structural properties on lithium-ion and sodium-ion storage: illustrated by the example of a micro-mesoporous graphene (MoS) anode.

In this work, we synthesized micro-mesoporous graphene (MoS) with different compositional ratios co-reduction of graphite oxide and exfoliated MoS platelets. We systematically studied the performance of the micro-mesoporous graphene (MoS) as anodes in lithium-ion batteries and sodium-ion batteries. The results show that the specific surface areas of the composites decrease with introducing MoS.

Ultra-Fine Ruthenium Oxide Quantum Dots/Reduced Graphene Oxide Composite as Electrodes for High-Performance Supercapacitors.

This study synthesized ultra-fine nanometer-scaled ruthenium oxide (RuO) quantum dots (QDs) on reduced graphene oxide (rGO) surface by a facile and rapid microwave-assisted hydrothermal approach. Benefiting from the synergistic effect of RuO and rGO, RuO/rGO nanocomposite electrodes showed ultra-high capacitive performance. The impact of different RuO loadings in RuO/rGO nanocomposite on their electrochemical performance was investigated by various characterizations.

Energy-Saving Synthesis of Functional CoS/rGO Interlayer With Enhanced Conversion Kinetics for High-Performance Lithium-Sulfur Batteries.

Lithium sulfur (Li-S) battery has exhibited great application potential in next-generation high-density secondary battery systems due to their excellent energy density and high specific capacity. However, the practical industrialization of Li-S battery is still affected by the low conductivity of sulfur and its discharge product (LiS/LiS), the shuttle effect of lithium polysulfide (LiS, 4 ≤ n ≤ 8) during charging/discharging process and so on. Here, cobalt disulfide/reduced graphene oxide (CoS/rGO) composites were easily and efficiently prepared through an energy-saving microwave-assisted hydrothermal method and employed as functional interlayer on commercial polypropylene separator to enhance the electrochemical performance of Li-S battery.

A stable LaB nanoneedle field-emission point electron source.

A material with a low work function exhibiting field-emission of electrons has long been sought as an ideal point electron source to generate a coherent electron beam with high brightness, long service life, low energy spread, and especially stable emission current. The quality and performance of the electron source are now becoming limiting factors for further improving the spatial resolution and analytical capabilities of the electron microscope. While tungsten (W) is still the only material of choice as a practically usable field emission filament since it was identified more than six decades ago, its electron optical performance remains unsatisfactory, especially the poor emission stability (>5% per hour), rapid current decay (20% in 10 hours), and relatively large energy spread (0.

Electrical conduction and field emission of a single-crystalline GdBSi nanowire.

The electronic transport and field emission properties of a single-crystalline GdB44Si2 nanowire are studied. The atomic structure and elemental composition of the GdB44Si2 nanowire are characterized by transmission electron microscopy (TEM) using atomic imaging, energy-dispersive X-ray spectroscopy (EDS), and electron energy-loss spectroscopic (EELS) mapping. The electrical conductivity of the single GdB44Si2 nanowire is in the range of 46.

Cellulose-Derived Highly Porous Three-Dimensional Activated Carbons for Supercapacitors.

A novel "selective surface dissolution" (SSD) method was successfully utilized in previous research to prepare "all-polymer composites" aiming to structural applications. In the current study, this simple, cost-effective, and environmentally friendly method was employed for the first time to synthesize cellulose-derived highly porous three-dimensional (3D) activated carbon materials to assemble superior electrodes for supercapacitors. ZnCl aqueous solution was used to partially dissolve the surface of cellulose fibers.

Unique interconnected graphene/SnO nanoparticle spherical multilayers for lithium-ion battery applications.

We have designed and synthesized a unique structured graphene/SnO composite, where SnO nanoparticles are inserted in between interconnected graphene sheets which form hollow spherical multilayers. The hollow spherical multilayered structure provides much flexibility to accommodate the configuration and volume changes of SnO in the material. When it is used as an anode material for lithium-ion batteries, such a novel nanostructure can not only provide a stable conductive matrix and suppress the mechanical stress, but also eliminate the need of any binders for constructing electrodes.

Comparison of reduction products from graphite oxide and graphene oxide for anode applications in lithium-ion batteries and sodium-ion batteries.

Hydrazine-reduced graphite oxide and graphene oxide were synthesized to compare their performances as anode materials in lithium-ion batteries and sodium-ion batteries. Reduced graphite oxide inherits the layer structure of graphite, with an average spacing between neighboring layers (d-spacing) of 0.374 nm; this exceeds the d-spacing of graphite (0.

An ultrabright and monochromatic electron point source made of a LaB6 nanowire.

Electron sources in the form of one-dimensional nanotubes and nanowires are an essential tool for investigations in a variety of fields, such as X-ray computed tomography, flexible displays, chemical sensors and electron optics applications. However, field emission instability and the need to work under high-vacuum or high-temperature conditions have imposed stringent requirements that are currently limiting the range of application of electron sources. Here we report the fabrication of a LaB6 nanowire with only a few La atoms bonded on the tip that emits collimated electrons from a single point with high monochromaticity.

Nanostructured LaB6 field emitter with lowest apical work function.

LaB(6) nanowires are ideal for applications as an electrical field-induced ion and electron point source due to their miniature dimensions, low work function, as well as excellent electrical, thermal, and mechanical properties. We present here a reliable method to fabricate and assemble single LaB(6) nanowire-based field emitters of different crystal orientations. The atomic arrangement, emission brightness from each crystal plane, and field emission stability have been characterized using field ion microscopy (FIM) and field emission microscopy (FEM).