Vanadium Oxide Nanofibers: Synthesis and Research on Functional Properties

2020 ◽  
Vol 12 (1) ◽  
pp. 68-74 ◽  
Author(s):  
O. Ya. Berezina ◽  
N.P. Markova ◽  
E.N. Kolobova ◽  
A.L. Pergament ◽  
D.S. Yakovleva ◽  
...  
Keyword(s):  
Vanadium Oxide ◽  
Electrode Materials ◽  
Sol Gel ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrospinning Method ◽  
Metal Phase Transition ◽  
Li Ion ◽  
Optical Laser

Aim: Vanadium oxide nanofibers have been manufactured by the sol–gel electrospinning method followed by the thermal treatment in air and argon. Materials and Methods: The samples are characterized by optical, laser confocal and scanning electron microscopy, energy-dispersive X-ray elemental analysis, X-ray diffraction, cyclic voltammetry, and electrical conductivity measurements. Results: The obtained VO2 nanofibers demonstrate the semiconductor-to-metal phase transition. Also, the vanadium pentoxide nanofibers are examined as electrode materials for rechargeable Li-ion batteries.

Lithium chromium pyrophosphate as an insertion material for Li-ion batteries

2015 ◽  
Vol 71 (6) ◽  
pp. 661-667 ◽  
Author(s):  
Martin Reichardt ◽  
Sébastien Sallard ◽  
Petr Novák ◽  
Claire Villevieille
Keyword(s):  
Sol Gel ◽  
Insertion Reaction ◽  
Li Ion Batteries ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Theoretical Limit ◽  
X Ray ◽  
Electrochemically Active ◽  
Carbon Coated ◽  
Li Ion

Lithium chromium pyrophosphate (LiCrP2O7) and carbon-coated LiCrP2O7 (LiCrP2O7/C) were synthesized by solid-state and sol–gel routes, respectively. The materials were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and conductivity measurements. LiCrP2O7 powder has a conductivity of ∼ 10−8 S cm−1, ∼ 104 times smaller than LiCrP2O7/C (∼ 10−4 S cm−1). LiCrP2O7/C is electrochemically active, mainly between 1.8 and 2.2 V versus Li+/Li (Cr3+/Cr2+ redox couple), whereas LiCrP2O7 has limited electrochemical activity. LiCrP2O7/C delivers a reversible specific charge up to ∼ 105 mAh g−1 after 100 cycles, close to the theoretical limit of 115 mAh g−1. Operando XRD experiments show slight peak shifts between 2.2 and 4.8 V versus Li+/Li, and a reversible amorphization between 1.8 and 2.2 V versus Li+/Li, suggesting an insertion reaction mechanism.

Low-Temperature Performance of the Li[Li0.2Co0.4Mn0.4]O2 Cathode Material Studied for Li-Ion Batteries

2011 ◽  
Vol 347-353 ◽  
pp. 3662-3665 ◽  
Author(s):  
Yu Hui Wang ◽  
Zhe Li ◽  
Kai Zhu ◽  
Gang Li ◽  
Ying Jin Wei ◽  
...  
Keyword(s):  
Low Temperature ◽  
Cathode Material ◽  
Room Temperature ◽  
Sol Gel ◽  
Cycle Performance ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
X Ray ◽  
Li Ion

The Li[Li0.2Co0.4Mn0.4]O2 cathode material was prepared by a sol-gel method. Combinative X-ray diffraction (XRD) studies showed that the material was a solid solution of LiCoO2 and Li2MnO3. The material showed a reversible discharge capacity of 155.0 mAhg−1 at -20 °C, which is smaller than that at room temperature (245.5 mAhg−1). However, the sample exhibited capacity retention of 96.3 % at -20 °C, only 74.2 % at 25 °C. The good electrochemical cycle performance at low temperature was due to the inexistence of Mn3+ in the material.

scholarly journals Doped Nanoscale NMC333 as Cathode Materials for Li-Ion Batteries

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2899 ◽  
Author(s):  
Hashem ◽  
Abdel-Ghany ◽  
Scheuermann ◽  
Indris ◽  
Ehrenberg ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Chelating Agent ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
Al Doping ◽  
X Ray ◽  
Transmission Electron ◽  
Li Ion ◽  
Diffraction Patterns

A series of Li(Ni1/3Mn1/3Co1/3)1−xMxO2 (M = Al, Mg, Zn, and Fe, x = 0.06) was prepared via sol-gel method assisted by ethylene diamine tetra acetic acid as a chelating agent. A typical hexagonal α-NaFeO2 structure (R-3m space group) was observed for parent and doped samples as revealed by X-ray diffraction patterns. For all samples, hexagonally shaped nanoparticles were observed by scanning electron microscopy and transmission electron microscopy. The local structure was characterized by infrared, Raman, and Mössbauer spectroscopy and 7Li nuclear magnetic resonance (Li-NMR). Cyclic voltammetry and galvanostatic charge-discharge tests showed that Mg and Al doping improved the electrochemical performance of LiNi1/3Mn1/3Co1/3O2 in terms of specific capacities and cyclability. In addition, while Al doping increases the initial capacity, Mg doping is the best choice as it improves cyclability for reasons discussed in this work.

Using In Situ High-Energy X-ray Diffraction to Quantify Electrode Behavior of Li-Ion Batteries from Extreme Fast Charging

2021 ◽  
Author(s):  
Partha P. Paul ◽  
Chuntian Cao ◽  
Vivek Thampy ◽  
Hans-Georg Steinrück ◽  
Tanvir R. Tanim ◽  
...  
Keyword(s):  
High Energy ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fast Charging ◽  
Li Ion

Phase Transformation Behavior and Stability of LiNiO 2 Cathode Material for Li‐Ion Batteries Obtained from In Situ Gas Analysis and Operando X‐Ray Diffraction

ChemSusChem ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 2240-2250 ◽  
Author(s):  
Lea de Biasi ◽  
Alexander Schiele ◽  
Maria Roca‐Ayats ◽  
Grecia Garcia ◽  
Torsten Brezesinski ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Cathode Material ◽  
Gas Analysis ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
Transformation Behavior ◽  
X Ray ◽  
Phase Transformation Behavior ◽  
Li Ion

High-Performance Li-Ion Batteries Using Nickel-Rich Lithium Nickel Cobalt Aluminium Oxide–Nanocarbon Core–Shell Cathode: In Operando X-ray Diffraction

2019 ◽  
Vol 11 (34) ◽  
pp. 30719-30727 ◽  
Author(s):  
Selvamani Vadivel ◽  
Nutthaphon Phattharasupakun ◽  
Juthaporn Wutthiprom ◽  
Salatan duangdangchote ◽  
Montree Sawangphruk
Keyword(s):  
High Performance ◽  
Aluminium Oxide ◽  
Core Shell ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Cobalt ◽  
Li Ion ◽  
In Operando

Structural complexity of layered-spinel composite electrodes for Li-ion batteries

2010 ◽  
Vol 25 (8) ◽  
pp. 1601-1616 ◽  
Author(s):  
Jordi Cabana ◽  
Christopher S. Johnson ◽  
Xiao-Qing Yang ◽  
Kyung-Yoon Chung ◽  
Won-Sub Yoon ◽  
...  
Keyword(s):  
Structural Complexity ◽  
Composite Electrodes ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Li Ion ◽  
Excess Phase ◽  
X Ray Absorption

The complexity of layered-spinel yLi2MnO3·(1 – y)Li1+xMn2–xO4 (Li:Mn = 1.2:1; 0 ≤ x ≤ 0.33; y ≥ 0.45) composites synthesized at different temperatures has been investigated by a combination of x-ray diffraction (XRD), x-ray absorption spectroscopy (XAS), and nuclear magnetic resonance (NMR). While the layered component does not change substantially between samples, an evolution of the spinel component from a high to a low lithium excess phase has been traced with temperature by comparing with data for pure Li1+xMn2–xO4. The changes that occur to the structure of the spinel component and to the average oxidation state of the manganese ions within the composite structure as lithium is electrochemically removed in a battery have been monitored using these techniques, in some cases in situ. Our 6Li NMR results constitute the first direct observation of lithium removal from Li2MnO3 and the formation of LiMnO2 upon lithium reinsertion.

Electrochemical Behavior of LiCo(1-x)MnxO2 Crystalline Powders

2014 ◽  
Vol 895 ◽  
pp. 334-337
Author(s):  
Azira Azahidi ◽  
Norlida Kamarulzaman ◽  
Kelimah Elong ◽  
Nurhanna Badar ◽  
Nurul Atikah Mohd Mokhtar
Keyword(s):  
Partial Substitution ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
X Ray ◽  
Capacity Loss ◽  
Transition Metal Element ◽  
Metal Element ◽  
Li Ion ◽  
Mn Doped

LiCoO2 is a well-known cathode material used in commercial Li-ion batteries but it has its own limitations in terms of cost and toxicity. Improvement of the material by partial substitution of Co with other transition metals is one of the alternative and effective ways to overcome the limitations and improve the electrochemical performance of cathode materials. The transition metal element used for the substitution has to be cheaper and non-toxic thus Mn is chosen here. LiCo(1-x)MnxO2 (x= 0.1, 0.2, 0.3) we synthesized by a novel route using a self-propagating combustion (SPC) method. The samples are analyzed using X-Ray Diffraction (XRD) for phase purity and Field Emission Scanning Electron Microscopy (FESEM) for morphology and particle size studies. The materials obtained are phase pure. In terms of electrochemical activity, though it does not show better first cycle discharge capacity, the Mn doped materials have improved capacity retention. Results showed that LiCo0.9Mn0.1O2 and LiCo0.8Mn0.2O2 exhibited less than 8 % capacity loss in the 20th cycle compared to 12 % for LiCoO2.

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