scholarly journals Oxidizing Roasting Behavior and Leaching Performance for the Recovery of Spent LiFePO4 Batteries

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 949
Author(s):  
Yafei Jie ◽  
Shenghai Yang ◽  
Yun Li ◽  
Duoqiang Zhao ◽  
Yanqing Lai ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Cathode Materials ◽  
Photoelectron Spectroscopy ◽  
Performance Test ◽  
Fluorine Content ◽  
Acid Leaching ◽  
X Ray ◽  
Al Content ◽  
Negative Effect ◽  
Roasting Temperature

In this study, the effects of oxidizing roasting process on the liberation of cathode materials from Al foil under different conditions were investigated systematically. The mineralogical characteristics of the cathode materials before and after thermal treatment were extensively characterized using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) as well as Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The results indicated that the increase in roasting temperature, oxygen concentration, and air flow rate enhanced the liberation of cathode materials. The cathode materials were gradually oxidized to Li3Fe2(PO4)3 and Fe2O3. Further, the carbon and fluorine content in the cathode materials decreased slowly during the thermal treatment, while the Al content increased. When the roasting temperature exceeded the melting point of Al, the Al foils were ablated and the cathode materials adhered to the Al foils again, resulting in difficulty in separation. The cathode materials leaching performance test results demonstrated that the oxidation of cathode materials had a negative effect on the leaching of Fe in sulfuric acid leaching system.

scholarly journals Impact of high temperatures on aluminoceladonite studied by Mössbauer, Raman, X-ray diffraction and X-ray photoelectron spectroscopy

2021 ◽  
Author(s):  
Mariola Kądziołka-Gaweł ◽  
Maria Czaja ◽  
Mateusz Dulski ◽  
Tomasz Krzykawski ◽  
Magdalena Szubka
Keyword(s):  
Photoelectron Spectroscopy ◽  
Integral Intensity ◽  
Photoelectron Spectra ◽  
X Ray Diffraction ◽  
Structural Reorganization ◽  
Oh Groups ◽  
X Ray ◽  
Al Content ◽  
Integral Intensity Ratio ◽  
Higher Temperature

AbstractMössbauer, Raman, X-ray diffraction and X-ray photoelectron spectroscopies were used to examine the effects of temperature on the structure of two aluminoceladonite samples. The process of oxidation of Fe2+ to Fe3+ ions started at about 350 °C for the sample richer in Al and at 300 °C for the sample somewhat lower Al-content. Mössbauer results show that this process may be associated with dehydroxylation or even initiate it. The first stage of dehydroxylation takes place at a temperature > 350 °C when the adjacent OH groups are replaced with a single residual oxygen atom. Up to ~500 °C, Fe ions do not migrate from cis-octahedra to trans-octahedra sites, but the coordination number of polyhedra changes from six to five. This temperature can be treated as the second stage of dehydroxylation. The temperature dependence on the integral intensity ratio between bands centered at ~590 and 705 cm−1 (I590/I705) clearly reflects the temperature at which six-coordinated polyhedra are transformed into five-coordinated polyhedra. X-ray photoelectron spectra obtained in the region of the Si2p, Al2p, Fe2p, K2p and O1s core levels, highlighted a route to identify the position of Si, Al, K and Fe cations in a structure of layered silicates with temperature. All the measurements show that the sample with a higher aluminum content and a lower iron content in octahedral sites starts to undergo a structural reorganization at a relatively higher temperature than the less aluminum-rich sample does. This suggests that iron may perform an important role in the initiation of the dehydroxylation of aluminoceladonites.

scholarly journals Decolorization of Methylene Blue by Ag/SrSnO3 Composites under Ultraviolet Radiation

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Patcharanan Junploy ◽  
Titipun Thongtem ◽  
Somchai Thongtem ◽  
Anukorn Phuruangrat
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Separation Process ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Negative Effect ◽  
Uv Visible

SrSn(OH)6 precursors synthesized by a cyclic microwave radiation (CMR) process were calcined at 900°C for 3 h to form rod-like SrSnO3. Further, the rod-like SrSnO3 and AgNO3 in ethylene glycol (EG) were ultrasonically vibrated to form rod-like Ag/SrSnO3 composites, characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron microscopy (EM), Fourier transform infrared (FTIR) spectroscopy, and UV-visible analysis. The photocatalyses of rod-like SrSnO3, 1 wt%, 5 wt%, and 10 wt% Ag/SrSnO3 composites were studied for degradation of methylene blue (MB, C16H18N3SCl) dye under ultraviolet (UV) radiation. In this research, the 5 wt% Ag/SrSnO3 composites showed the highest activity, enhanced by the electron-hole separation process. The photoactivity became lower by the excessive Ag nanoparticles due to the negative effect caused by reduction in the absorption of UV radiation.

scholarly journals Enhanced Electrochemical Performances of Cobalt-Doped Li2MoO3 Cathode Materials

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 843 ◽  
Author(s):  
Zhiyong Yu ◽  
Jishen Hao ◽  
Wenji Li ◽  
Hanxing Liu
Keyword(s):  
Cathode Materials ◽  
Photoelectron Spectroscopy ◽  
Solid Phase ◽  
Phase Method ◽  
Electrochemical Performances ◽  
X Ray ◽  
Electrochemical Tests ◽  
Co Doping ◽  
Solid Phase Method ◽  
Better Than

Co-doped Li2MoO3 was successfully synthesized via a solid phase method. The impacts of Co-doping on Li2MoO3 have been analyzed by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) measurements. The results show that an appropriate amount of Co ions can be introduced into the Li2MoO3 lattices, and they can reduce the particle sizes of the cathode materials. Electrochemical tests reveal that Co-doping can significantly improve the electrochemical performances of the Li2MoO3 materials. Li2Mo0.90Co0.10O3 presents a first-discharge capacity of 220 mAh·g−1, with a capacity retention of 63.6% after 50 cycles at 5 mA·g−1, which is much better than the pristine samples (181 mAh·g−1, 47.5%). The enhanced electrochemical performances could be due to the enhancement of the structural stability, and the reduction in impedance, due to the Co-doping.

scholarly journals Evaluation of Solar-Driven Photocatalytic Activity of Thermal Treated TiO2 under Various Atmospheres

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 163 ◽  
Author(s):  
Reza Katal ◽  
Saeideh Kholghi Eshkalak ◽  
Saeid Masudy-panah ◽  
Mohammadreza Kosari ◽  
Mohsen Saeedikhani ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Thermal Treatment ◽  
Oxygen Vacancy ◽  
Photoelectron Spectroscopy ◽  
Significant Feature ◽  
Positive Role ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Treatment Conditions ◽  
Treated Sample

In this report, the photocatalytic activity of P25 has been explored and the influence of thermal treatment under various atmospheres (air, vacuum and hydrogen) were discussed. The samples’ characteristics were disclosed by means of various instruments including X-ray diffraction (XRD), Electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS) and UV–vis. This study also accentuates various states of the oxygen vacancy density formed inside the samples as well as the colour turning observed in treated P25 under various atmospheres. Produced coloured TiO2 samples were then exploited for their photocatalytic capability concerning photodegradation of methylene blue (MB) using air mass (AM) 1.5 G solar light irradiation. Our findings revealed that exceptional photocatalytic activity of P25 is related to the thermal treatment. Neither oxygen vacancy formation nor photocatalytic activity enhancement was observed in the air-treated sample. H2-treated samples have shown better photoactivity which even could be further improved by optimizing treatment conditions to achieve the advantages of the positive role of oxygen vacancy (O-vacancy at higher concentration than optimum acts as electron trapping sites). The chemical structure and stability of the samples were also studied. There was no sign of deteriorating of O2-vacancies inside the samples after 6 months. High stability of thermal treated samples in terms of both long and short-term time intervals is another significant feature of the produced photocatalyst.

HAFNIUM AND NITROGEN INTERACTION AT Hf/GaN(0001) INTERFACE

2020 ◽  
Vol 27 (11) ◽  
pp. 2050013
Author(s):  
RAFAŁ LEWANDKÓW ◽  
RADOSŁAW WASIELEWSKI ◽  
PIOTR MAZUR
Keyword(s):  
Thermal Treatment ◽  
Photoelectron Spectroscopy ◽  
Molecular Nitrogen ◽  
Native Oxide ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Atomic Nitrogen ◽  
Stable Layer ◽  
Xps Spectra ◽  
X Ray ◽  
Strong Shift

The growth and stability of hafnium films on [Formula: see text]-GaN(0001) surface with native oxide was investigated with X-ray and ultraviolet photoelectron spectroscopy (XPS, UPS). It is shown that hafnium creates a continuous and stable layer on GaN substrate. Thermal treatment at [Formula: see text]C of Hf/GaN system causes decomposition of GaN and reaction of hafnium with atomic nitrogen from the substrate. XPS spectra demonstrate the reaction by a strong shift of the N 1s and Hf 4f lines. An attempt for bringing on the same reaction with molecular nitrogen under pressure of [Formula: see text] mbar was not successful. UPS spectra show a metallic character of the hafnium adlayer in such instances.

Preparation and Effect of (3-aminopropyl)triethoxysilane-Coated LiNi0.5Co0.2Mn0.3O2 Cathode Material for Lithium Ion Batteries

2020 ◽  
Vol 20 (6) ◽  
pp. 3460-3465
Author(s):  
Mi-Ra Shin ◽  
Seon-Jin Lee ◽  
Seong-Jae Kim ◽  
Tae-Whan Hong
Keyword(s):  
Cathode Material ◽  
Lithium Ion Batteries ◽  
Cathode Materials ◽  
Photoelectron Spectroscopy ◽  
Coating Layer ◽  
Lithium Ion ◽  
X Ray ◽  
Amine Groups ◽  
Coating Layers ◽  
Discharge Capacities

Surface coating using (3-aminopropyl)triethoxysilane (APTES) has been applied to improve the electrochemical properties of LiNi0.5Co0.2Mn0.3O2 (NCM523) cathode materials. The APTES coating layer on the surface of NCM523 protects the direct contact area between the cathode material and the electrolyte, and facilitates the presence of electrons through the abundance of electron-rich amine groups, thereby improving electrochemical performance. X-ray photoelectron spectroscopy confirmed the existence of APTES coating layers on the surface of NCM523 cathode materials, revealing three peaks—N1s, O1s, and Si1s—that were not identified in bare NCM523. In addition, the discharge capacities of the bare electrode and the APTES-coated NCM523 electrode were 121.06 mAh/g and 156.43 mAh/g, respectively. To the best of our knowledge, the use of an APTES coating on NCM523 cathode materials for lithium-ion batteries has never been reported.

Growth and Luminescence of N Doped TiO2 Nanowires

2008 ◽  
Vol 8 (12) ◽  
pp. 6533-6537 ◽  
Author(s):  
D. Maestre ◽  
A. Cremades ◽  
L. Gregoratti ◽  
J. Piqueras
Keyword(s):  
Thermal Treatment ◽  
Photoelectron Spectroscopy ◽  
Sample Surface ◽  
Tio2 Nanowires ◽  
Rutile Structure ◽  
Oxide Nanowires ◽  
X Ray ◽  
Oxide Nanostructures ◽  
Different Temperatures ◽  
N Incorporation

Titanium oxide nanowires have been grown by thermal treatment of pressed TiN powder under argon or N2 flow. It has been found that two-step treatments at two different temperatures, 400 °C and 800 °C, lead to the growth of nanowires all over the sample surface. The nanowires are of single crystalline rutile structure. Energy dispersive X-ray spectroscopy and photoelectron spectroscopy measurements show that the oxide nanostructures contain N from the starting nitride. The mechanism of N incorporation into the oxide and its possible effect on the luminescence are discussed.

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