Electrochemical performance of graphene nanosheets as anode material for lithium-ion batteries

Graphene nanosheets (GNSs) were prepared from artificial graphite by oxidation, rapid expansion and ultrasonic treatment. The morphology, structure and electrochemical performance of GNSs as anode material for lithium-ion batteries were systematically investigated by high-resolution transmission electron microscope, scanning electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy and a variety of electrochemical testing techniques. It was found that GNSs exhibited a relatively high reversible capacity of 672 mA h/g and fine cycle performance. The exchange current density of GNSs increased with the growth of cycle numbers exhibiting the peculiar electrochemical performance.     

Hydrothermal exfoliated molybdenum disulfide nanosheets as anode material for lithium ion batteries

Ultrathin MoS2nanosheets were prepared in high yield using a facile and effective hydrothermal intercalation and exfoliation route. The products were characterized in detail using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that the high yield of MoS2nanosheets with good quality was successfully achieved and the dimensions of the immense nanosheets reached 1 μm–2 μm. As anode material for Li-ion batteries, the as-prepared MoS2nanosheets electrodes exhibited a good initial capacity of 1190 mAh g-1and excellent cyclic stability at constant current density of 50 mA g-1. After 50 cycles, it still delivered reversibly sustained high capacities of 750 mAh g-1.     

Hydrothermal exfoliated molybdenum disulfide nanosheets as anode material for lithium ion batteries

Ultrathin MoS2nanosheets were prepared in high yield using a facile and effective hydrothermal intercalation and exfoliation route. The products were characterized in detail using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that the high yield of MoS2nanosheets with good quality was successfully achieved and the dimensions of the immense nanosheets reached 1 μm–2 μm. As anode material for Li-ion batteries, the as-prepared MoS2nanosheets electrodes exhibited a good initial capacity of 1190 mAh g-1and excellent cyclic stability at constant current density of 50 mA g-1. After 50 cycles, it still delivered reversibly sustained high capacities of 750 mAh g-1.     

Tremella-like molybdenum dioxide consisting of nanosheets as an anode material for lithium ion battery

Tremella-like structured MoO₂ consisting of nanosheets was obtained via a Fe₂O₃-assisted hydrothermal reduction of MoO₃ in ethylenediamine aqueous solution. The as-prepared product was characterized and tested with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and capacity measurement as anode material for lithium ion batteries. This structured MoO₂ shows very high reversible capacity (>600 mA h g⁻¹), good rate capability and cycling performance, presenting potential application as anode material for lithium ion batteries with high rate capability and high capacity.     

Synthesis and characterization of vanadium oxides nanorods

Vanadium oxides nanorods with high crystallinity and high surface area were synthesized by hydrothermal method using laurylamine hydrochloride, metal alkoxide and acetylacetone. The samples characterized by XRD, nitrogen adsorption isotherm, SEM, TEM, and SAED. Uniformly sized B phase VO₂ nanorods had widths about 40-80 nm and lengths reaching up to 1 μm. V₂O₅ rodlike structured with the widths about 100-500 nm and the lengths of 1-10 μm were obtained by calcination at 400 °C for 4 h. This synthesis method provides a new simple route to fabricate one-dimensional nanostructured metal oxides under mild conditions.     

Pb-sandwiched nanoparticles as anode material for lithium-ion batteries

A sandwiched SiC@Pb@C nanocomposite was prepared through a simple ball-milling route and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The SiC@Pb@C nanocomposite exhibits a much improved reversible capacity and cycling life as compared with a bare Pb anode. A reversible volumetric capacity of >1,586 mAh cm⁻³ (207 mAh g⁻¹) can be maintained after 600 cycles of charge and discharge in the potential interval between 0.005 and 1.0 V, which far exceeds those reported previously in the literature. The enhanced electrochemical performance is ascribed to the sandwiched structure in which nanosized Pb particles were anchored in between the rigid SiC core and the outer carbon shell, mitigating the damage done by the large volume change of the Pb interlayer during the alloying/dealloying process.     

Layer-by-layer engineered Co-Al hydroxide nanosheets/graphene multilayer films as flexible electrode for supercapacitor

Multilayer films of Co-Al layered double hydroxide nanosheets (Co-Al LDH-NS) and graphene oxide (GO) were fabricated through layer-by-layer (LBL) assembly. By using a three-electrode system, the electrochemical performances of the films were investigated to evaluate their potential as electrode materials to be used in flexible supercapacitor devices. The Co-Al LDH-NS/GO multilayer films exhibited a high specific capacitance of 880 F/g and area capacitance of 70 F/m(2) under the scan rate of 5 mV/s. And the film exhibited good cycle stability over 2000 cycles. After treating the films at 200 °C in H(2) atmosphere, the specific capacitance and area capacitance were largely increased up to 1204 F/g and 90 F/m(2) due to partial reduction of GO. A flexible electrode by depositing Co-Al LDH-NS/GO multilayer film onto PET substrate was prepared to show the potential of Co-Al LDH-NS/GO films for flexible energy storage.     

Preparation and characterization of oxides of Ni-Cu: anode material for methanol oxidative fuel cells

Oxides of Ni-Cu were electrodeposited and characterized by SEM, IR and XPS techniques. These studies indicate that the coatings are mostly amorphous, made up of tiny particles of copper metal or a very low alloy with nickel in non-metallic phases with non-stoichiometric compositions. The deposited oxide films exhibit low overvoltages at 303 K for methanol oxidation and act as effective anode materials. Electrocatalytic activity of the deposited films depends on the composition of the coating. Under working conditions the deposits exhibit good corrosion resistance towards the electrolyte medium.     

Nanostructured TiO2 as anode material for magnesium-ion batteries

Journal of Solid State Electrochemistry - The nanotubular structure of titanium dioxide (TiO2) is most suitable for creating high-performance energy storage and conversion devices. This paper...     

InP as new anode material for lithium ion batteries

InP thin film has been successfully fabricated by pulsed laser deposition (PLD) and was investigated for its electrochemistry with lithium for the first time. InP thin film presented a large reversible discharge capacity around 620 mAh g^?1. The reversibility of the crystalline structure and electrochemical reaction of InP with lithium were revealed by using ex situ XRD and XPS measurements. The high reversible capacity and stable cycle of InP thin film electrode with low overpotential made it one of the promise energy storage materials for future rechargeable lithium batteries.     

X-ray ultrasoft spectra of vanadium in vanadium oxides

The Lα-emission spectra of vanadium in oxides V₂O₃, VO₂, V₂O₅, V₃O₅, V₄O₇, V₆O₁₁, V₆O₁₃, and V₃O₇ are investigated. It is discovered that the charge fluctuations in V₃O₅, V₄O₇, and V₆O₁₁ have a period greater than the $\text{2p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ hole life-time (～10^?15 sec), while in V₆O₁₃ and V₃O₇ this period is less than 10^?15 sec.     

Novel binding material for supercapacitor electrodes

Environmentally friendly water-based composite material has been investigated as a novel binder for manufacturing supercapacitor electrodes. The performance of these electrodes and those with the conventional polyvinylidene fluoride (PVDF) binder were studied. Results obtained from cyclic voltammetry, electrochemical impedance spectrometry, and charge/discharge measurements showed that the electrodes with the new binder performed significantly better than the electrodes with the conventional PVDF binder; the specific capacitance increased by 51 % in an aqueous electrolyte while in an organic electrolyte, it increased by 15 %. This increase in capacitance was attributed to the electrophilic and hydrophilic nature of the new binding composite. The main reason for the improvement in capacitance was ascribed to reduction of equivalent series resistance (ESR). The presence of highly amorphous polyvinylpyrrolidone (PVP), a polymeric component of the new composite binder, was responsible for the reduction in ESR.     

Novel application of LiCoO_2 as a high-performance candidate material for supercapacitor

Electrochemical performances of LiCoO2 as a candidate material for supercapacitor are systematically investigated. LiCoO2 nanomaterials are synthesized via hydrothermal reaction with consequent calcination process. And the particle size increases as the calcination temperature rises.LCO-650 sample with the largest particle size displays the maximum capacitances of 817.5 Fg-1with the most outstanding capacity retention rate of 96.8% after 2000 cycles. It is shown that large particle size is beneficial to the electrochemical and structural stability of Li CoO2 materials. We speculate that the micron-sized waste LiCoO2 materials have great potential for supercapacitor application. It may provide a novel recovered approach for spent LIBs and effectively relieve the burdens on the resource waste and environment pollution.     

Bismuth nanosheets grown on carbon fiber cloth as advanced binder-free anode for sodium-ion batteries

The bismuth nanosheets grown on carbon fiber cloth were designed. For sodium-ion batteries, the Bi/CFC electrode exhibited a high reversible capacity of 350 and 240 mAh g^− 1 after 300 cycles at 50 and 200 mA g^− 1, as well as a good rate capability. Besides, the electrode displayed two flat potential profiles during the charge/discharge process. The results suggest that the Bi/CFC electrode has excellent potential as an anode for sodium-ion batteries.     

Expanded graphite as an intercalation anode material for lithium systems

The expanded graphite (BOCHEMIE a.s., Czech Republic) was tested as the material for anodes of lithium secondary batteries. The irreversible charge was lowered and the cyclability improved if the material was annealed in CO₂. The specific capacity approached theoretical value corresponding to the composition LiC₆.     

Synthesis of Ni3V2O8@graphene oxide nanocomposite as an efficient electrode material for supercapacitor applications

Journal of Solid State Electrochemistry - In the present investigation, we have synthesized Ni3V2O8@GO composite by co-precipitation method and designed as a new anode material for supercapacitor...     

Synthesis and characterization of ZnO-Al2 O3 oxides as energetic electro-catalytic material for glucose fuel cell

One of the thrust areas of research is to find an alternative fuel to meet the increasing demand for energy. Glucose is a good source of alternative fuel for clean energy and is easily available in abundance from both naturally occurring plants and industrial processes. Electrochemical oxidation of glucose in fuel cell requires high electro-catalytic surface of the electrode to produce the clean electrical energy with minimum energy losses in the cell. Pt and Pt based alloys exhibit high electro-catalytic properties but they are expensive. For energy synthesis at economically cheap price, non Pt based inexpensive high electro catalytic material is required. Electro synthesized ZnO-Al₂O₃ composite is found to exhibit high electro-catalytic properties for glucose oxidation. The Cyclic Voltammetry and Chronoamperometry curves reflect that the material is very much comparable to Pt as far as the maximum current and the steady state current delivered from the glucose oxidation are concerned. XRD image confirms the mixed oxide composite. SEM images morphology show increased 3D surface areas at higher magnification. This attributed high current delivered from electrochemical oxidation of glucose on this electrode surface.     

Synthesis and high rate properties of nanoparticled lithium cobalt oxides as the cathode material for lithium-ion battery

Nanoparticled lithium cobalt oxides were synthesized by coprecipitation in ethanol. Mechanical stirring was used to control the particle growth. The controlled grain size was below 100 nm with a narrow distribution. The structure has been examined using X-ray diffraction. On hand of an experimental cell it appears that the novel material has an exciting high charge and discharge rate: the capacity is 100 mA h/g for a 50C rate and 130 mA h/g for a 10C rate.