scholarly journals A Facile Synthesis of MoS2/g-C3N4 Composite as an Anode Material with Improved Lithium Storage Capacity

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1730 ◽  
Author(s):  
Ha Tran Huu ◽  
Xuan Dieu Nguyen Thi ◽  
Kim Nguyen Van ◽  
Sung Jin Kim ◽  
Vien Vo
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Performance ◽  
Photoelectron Spectroscopy ◽  
Gas Flow ◽  
Electrode Materials ◽  
High Capacity ◽  
Sodium Molybdate ◽  
Lithium Ion ◽  
Lithium Storage ◽  
X Ray

The demand for well-designed nanostructured composites with enhanced electrochemical performance for lithium-ion batteries electrode materials has been emerging. In order to improve the electrochemical performance of MoS2-based anode materials, MoS2 nanosheets integrated with g-C3N4 (MoS2/g-C3N4 composite) was synthesized by a facile heating treatment from the precursors of thiourea and sodium molybdate at 550 °C under N2 gas flow. The structure and composition of MoS2/g-C3N4 were confirmed by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis and elemental analysis. The lithium storage capability of the MoS2/g-C3N4 composite was evaluated, indicating high capacity and stable cycling performance at 1 C (A·g−1) with a reversible capacity of 1204 mA·h·g−1 for 200 cycles. This result is believed the role of g-C3N4 as a supporting material to accommodate the volume change and improve charge transport for nanostructured MoS2. Additionally, the contribution of the pseudocapacitive effect was also calculated to further clarify the enhancement in Li-ion storage performance of the composite.

Al-doped VO2(B) nanobelts as cathode material with enhanced electrochemical properties for lithium-ion batteries

2018 ◽  
Vol 11 (04) ◽  
pp. 1850068 ◽  
Author(s):  
Changlei Niu
Keyword(s):  
Electrochemical Performance ◽  
Cathode Material ◽  
Lithium Ion Batteries ◽  
Valence State ◽  
Electrode Materials ◽  
High Capacity ◽  
Lithium Ion ◽  
Lithium Storage ◽  
Free Standing ◽  
Lattice Volume

Aluminium has shown its superiority in stabilization of the monoclinic VO2(B) in free-standing nanobelts. In this paper, aluminium-doped VO2(B) nanobelts are successfully fabricated by a facile one-step hydrothermal method and used as cathode for lithium-ion battery. XPS results show that Al-doping promotes the formation of high valence state of vanadium in VO2(B) nanobelts. Due to the accommodation of valence state of vanadium and lattice volume, Al-doped VO2(B) nanobelts used as the cathode material for lithium-ion batteries exhibit better lithium storage properties with high capacity of 172[Formula: see text]mAh[Formula: see text]g[Formula: see text] and cycling stability than undoped VO2(B) nanobelts. This work demonstrates that the doping of aluminium can significantly enhance the electrochemical performance of VO2(B), suggesting that appropriate cationic doping is an efficient path to improve the electrochemical performance of electrode materials.

SURFACE DECORATION OF COMMERCIAL GRAPHITE MICROSPHERES WITH SMALL Si/C MICROSPHERES AS IMPROVED ANODE MATERIALS FOR Li-ION BATTERIES

2013 ◽  
Vol 01 (04) ◽  
pp. 1340017
Author(s):  
ZAILEI ZHANG ◽  
YANHONG WANG ◽  
MEIJU ZHANG ◽  
QIANGQIANG TAN ◽  
FABING SU
Keyword(s):  
Electron Microscopy ◽  
Composite Materials ◽  
Electrochemical Performance ◽  
Photoelectron Spectroscopy ◽  
Anode Materials ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Li Ion Batteries ◽  
X Ray ◽  
Li Ion

We report a facile chemical vapor deposition (CVD) method to grow silicon/carbon ( Si / C ) microspheres on commercial graphite microsphere (GMs) surface to prepare Si / C / GMs composite anode materials for Li -ion batteries. The CVD synthesis is conducted at 900°C using methyltrichlorosilane ( CH 3 SiCl 3) as both the Si and C precursor, which is a cheap byproduct in organosilane industry. The samples are characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, thermogravimetric analysis, Raman spectroscopy and X-ray photoelectron spectroscopy. It is found that the obtained Si / C / GMs composites are composed of Si nanocrystals, amorphous carbon and GMs. The CVD time significantly influences the morphology and electrochemical performance of the Si / C / GMs composite materials. The Si / C / GMs composite materials prepared at CVD condition of 900°C for 4 h possess improved electrochemical properties, showing a discharge capacity of 821.4 mAh g−1 at a rate of 50 mA g−1, and a good cycling performance (i.e., a reversible capacity of 565.2 mAh g−1 is retained after 50 cycles). The enhanced electrochemical performance is attributed to the formation of Si / C microsphere network among GMs, which increases the electronic conductivity and is able to buffer the large volume changes of Si during lithium ion insertion/extraction.

Engineering flexible carbon nanofibers concatenated MOFs-derived hollow octahedral CoFe2O4 as anode materials for enhanced lithium storage

2021 ◽  
Author(s):  
Fangfang Xue ◽  
Yangyang Li ◽  
Chen Liu ◽  
Zhigang Zhang ◽  
Jun Lin ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Anode Materials ◽  
Electrode Materials ◽  
Electronic Devices ◽  
High Capacity ◽  
Lithium Ion ◽  
Lithium Storage ◽  
Excellent Mechanical Property ◽  
Wearable Electronic ◽  
Wearable Electronic Devices

Constructing suitable electrode materials with high capacity and excellent mechanical property is indispensable for flexible lithium-ion batteries (LIBs) to satisfy the growing flexible and wearable electronic devices. Herein, a necklace-like...

Facile Synthesis of Modified MnO2/Reduced Graphene Oxide Nanocomposites and their Application in Supercapacitors

NANO ◽  
2020 ◽  
Vol 15 (08) ◽  
pp. 2050099
Author(s):  
Lijun Chen ◽  
Hongfeng Yin ◽  
Yuchao Zhang ◽  
Huidong Xie
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Electrode Materials ◽  
Normal Pressure ◽  
X Ray ◽  
Assembly Method ◽  
Reduced Graphene

Herein, KH-550 was used as surface modifier to prepare modified MnO2/reduced graphene oxide (M-MnO2/rGO) composite electrode materials by utilizing electrostatic interaction at low temperature and normal pressure. X-ray diffraction, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy were adopted to characterize the material’s phase, morphology, and valence state of elements. The electrochemical properties of the material were measured using a three-electrode system. The results indicate a decrease in the size of the modified MnO2 particles, and that they were uniformly distributed on the rGO sheets. The M-MnO2/rGO composite attained a specific capacitance of 326[Formula: see text]F[Formula: see text]g[Formula: see text] in a solution of 1[Formula: see text]mol[Formula: see text]L[Formula: see text] Na2SO4 at a current density of 0.5[Formula: see text]A[Formula: see text]g[Formula: see text]. The specific capacitance of the material was 92.4% after 1000 cycles. The electrostatic self-assembly method effectively solved the problem of reducing the cycling stability while improving the specific capacitance of the composite materials, and further improved the possibility of applying MnO2/rGO in the field of supercapacitors.

scholarly journals Centrifugally Spun α-Fe2O3/TiO2/Carbon Composite Fibers as Anode Materials for Lithium-Ion Batteries

2019 ◽  
Vol 9 (19) ◽  
pp. 4032 ◽  
Author(s):  
Luis Zuniga ◽  
Gabriel Gonzalez ◽  
Roberto Orrostieta Chavez ◽  
Jason C. Myers ◽  
Timothy P. Lodge ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Composite Fiber ◽  
Carbon Composite ◽  
Composite Fibers ◽  
X Ray ◽  
Binder Free

We report results on the electrochemical performance of flexible and binder-free α-Fe2O3/TiO2/carbon composite fiber anodes for lithium-ion batteries (LIBs). The composite fibers were produced via centrifugal spinning and subsequent thermal processing. The fibers were prepared from a precursor solution containing PVP/iron (III) acetylacetonate/titanium (IV) butoxide/ethanol/acetic acid followed by oxidation at 200 °C in air and then carbonization at 550 °C under flowing argon. The morphology and structure of the composite fibers were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). These ternary composite fiber anodes showed an improved electrochemical performance compared to the pristine TiO2/C and α-Fe2O3/C composite fiber electrodes. The α-Fe2O3/TiO2/C composite fibers also showed a superior cycling performance with a specific capacity of 340 mAh g−1 after 100 cycles at a current density of 100 mA g−1, compared to 61 mAh g−1 and 121 mAh g−1 for TiO2/C and α-Fe2O3/C composite electrodes, respectively. The improved electrochemical performance and the simple processing of these metal oxide/carbon composite fibers make them promising candidates for the next generation and cost-effective flexible binder-free anodes for LIBs.

scholarly journals From Allergens to Battery Anodes: Nature-Inspired, Pollen Derived Carbon Architectures for Room- and Elevated- Temperature Li-ion Storage

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Jialiang Tang ◽  
Vinodkumar Etacheri ◽  
Vilas G. Pol
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Charge Transfer Resistance ◽  
High Rate ◽  
Energy Storage Devices ◽  
Lithium Storage ◽  
Transfer Resistance ◽  
Carbonaceous Particles ◽  
X Ray

Abstract The conversion of allergic pollen grains into carbon microstructures was carried out through a facile, one-step, solid-state pyrolysis process in an inert atmosphere. The as-prepared carbonaceous particles were further air activated at 300 °C and then evaluated as lithium ion battery anodes at room (25 °C) and elevated (50 °C) temperatures. The distinct morphologies of bee pollens and cattail pollens are resembled on the final architecture of produced carbons. Scanning Electron Microscopy images shows that activated bee pollen carbon (ABP) is comprised of spiky, brain-like and tiny spheres; while activated cattail pollen carbon (ACP) resembles deflated spheres. Structural analysis through X-ray diffraction and Raman spectroscopy confirmed their amorphous nature. X-ray photoelectron spectroscopy analysis of ABP and ACP confirmed that both samples contain high levels of oxygen and small amount of nitrogen contents. At C/10 rate, ACP electrode delivered high specific lithium storage reversible capacities (590 mAh/g at 50 °C and 382 mAh/g at 25 °C) and also exhibited excellent high rate capabilities. Through electrochemical impedance spectroscopy studies, improved performance of ACP is attributed to its lower charge transfer resistance than ABP. Current studies demonstrate that morphologically distinct renewable pollens could produce carbon architectures for anode applications in energy storage devices.

Thickness of carbon coatings on silicon materials determined by hard X-ray photoelectron spectroscopy at multiple photon energies

2019 ◽  
Vol 26 (6) ◽  
pp. 1936-1939 ◽  
Author(s):  
Noritake Isomura ◽  
Naoko Takahashi ◽  
Satoru Kosaka ◽  
Hiroyuki Kawaura
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Secondary Electron ◽  
Lithium Ion ◽  
Cross Sectional ◽  
Carbon Coatings ◽  
X Ray ◽  
Negative Electrodes ◽  
Silicon Materials ◽  
Microscopy Images

Hard X-ray photoelectron spectroscopy at multiple photon energies is used to investigate the surface structure of carbon coatings on silicon materials destined for use as negative electrodes in lithium-ion batteries. The photoelectron intensity from the carbon coatings decreases with an increase in the kinetic energy of the photoelectron. By fitting the photoelectron intensity versus energy to numerically derived curves, the thickness and coverage of the carbon coatings can be obtained. The results are in agreement with the values suggested by the cross-sectional secondary-electron microscopy images of the carbon coatings, although the thickness should be corrected by accounting for the rectangular parallelepiped structure of the silicon material.

Synthesis of MoO3/V2O5/C Composite as Novel Anode for Li-Ion Battery Application

2020 ◽  
Vol 20 (5) ◽  
pp. 2911-2916
Author(s):  
Zhen Zhang ◽  
Xiao Chen ◽  
Guangxue Zhang ◽  
Chuanqi Feng
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Li Ion Battery ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Li Ion ◽  
Battery Application

The MoO3/V2O5/C, MoO3/C and V2O5/C are synthesized by electrospinning combined with heat treatment. These samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and thermogravimetric analysis (TG) techniques. The results show that sample MoO3/V2O5/C is a composite composed from MoO3, V2O5 and carbon. It takes on morphology of the nanofibers with the diameter of 200~500 nm. The TG analysis result showed that the carbon content in the composite is about 40.63%. Electrochemical properties for these samples are studied. When current density is 0.2 A g−1, the MoO3/V2O5/C could retain the specific capacity of 737.6 mAh g−1 after 200 cycles and its coulomb efficiency is 92.99%, which proves that MoO3/V2O5/C has better electrochemical performance than that of MoO3/C and V2O5/C. The EIS and linear Warburg coefficient analysis results show that the MoO3/V2O5/C has larger Li+ diffusion coefficient and superior conductivity than those of MoO3/C or V2O5/C. So MoO3/V2O5/C is a promising anode material for lithium ion battery application.

scholarly journals Eco-friendly synthesis of VO 2 with stripped pentavalent vanadium solution extracted from vanadium-bearing shale by hydrothermal process in high conversion rate

2019 ◽  
Vol 6 (2) ◽  
pp. 181116 ◽  
Author(s):  
Qian Kang ◽  
Yimin Zhang ◽  
Shenxu Bao ◽  
Guobin Zhang
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Conversion Rate ◽  
Hydrothermal Process ◽  
Lithium Ion ◽  
Raw Material ◽  
High Concentration ◽  
X Ray ◽  
Pentavalent Vanadium ◽  
High Conversion Rate

VO 2 (B) has shown excellent cathode performance in lithium batteries and become a hot research topic in recent years. A stripped vanadium solution extracted from vanadium-bearing shale containing a high concentration of vanadium and certain amounts of impurities was used as a vanadium source to synthesize VO 2 (B) by hydrothermal process. The VO 2 conversion rate can reach as high as 99.47% in a reaction time of 8 h, and this is the highest result reported. The crystalline structure and morphology of the synthesized products were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Furthermore, the electrochemical properties of VO 2 (B) in lithium-ion batteries were investigated. The results indicated that the VO 2 (B) has the initial specific discharge capacity of 192.0 mAh g −1 . Stripped vanadium solution is a raw material for producing V 2 O 5 and NH 4 VO 3 , which are indispensable vanadium sources in VO 2 synthesis. Therefore, synthesis of VO 2 via hydrothermal reduction by oxalic acid using stripped vanadium solution extracted from vanadium-bearing shale as a direct vanadium source is an eco-friendly, innovative and efficient method, and will have a great impact on VO 2 synthesis.

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