Enhanced Electrochemical Performances of Ni-Rich LiNi0.8Co0.15Al0.05O2 Cathode Materials by Ti Doping or/and Al(OH)3 Coating

2020 ◽  
Vol 12 (9) ◽  
pp. 1283-1288 ◽  
Author(s):  
Un-Gi Han ◽  
Yeon-Ju Lee ◽  
Gyu-Bong Cho ◽  
Su-Gun Lim ◽  
Ki-Won Kim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Field Emission ◽  
Cathode Materials ◽  
Electrochemical Techniques ◽  
Cycling Stability ◽  
Side Reactions ◽  
Electrochemical Performances ◽  
Layer Spacing ◽  
X Ray ◽  
Ti Doping

To improve the electrochemical properties of Ni-rich LiNi0.8Co0.15Al0.05O2 (LiNCA) cathode material, Ti doped or/and Al(OH)3 coated were by co-precipitation-assisted solid-phase and ball milling method was employed in this work. The morphology, structure, and electrochemical performance of the cathode materials were evaluated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectrometer (EDS), field emission transmission electron microscopy (FETEM) and electrochemical techniques. Ti doping is introduced into the octahedral lattice space occupied by Li-ions to widen the Li layer spacing and thereby increase the lithium diffusion kinetics. The Al(OH)3 coating also formed a non-uniform layer on the outside of LiNCA, thereby inhibiting side reactions between the electrode and the electrolyte. As a result, the LiNCA electrode showed a high initial discharge capacity of 167.4 mAh/g. However, after 100 cycles, it showed poor cycling stability of 41.7%. In contrast, Ti doped and Al(OH)3 coated LiNCA showed the best cycling stability of 82.2% after 100 cycles.

Improved structural and electrochemical performances of LiNi0.5Mn1.5O4 cathode materials by Cr3+ and/or Ti4+ doping

RSC Advances ◽  
2015 ◽  
Vol 5 (121) ◽  
pp. 99856-99865 ◽  
Author(s):  
Li Wang ◽  
Dan Chen ◽  
Jiangfeng Wang ◽  
Guijuan Liu ◽  
Wei Wu ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Electrochemical Performance ◽  
Cathode Materials ◽  
Rate Capability ◽  
Cycling Stability ◽  
Electrochemical Performances ◽  
Ion Diffusion ◽  
Ti Doping ◽  
Co Doped

The Cr and/or Ti doping leads to the enhanced rate capability and cycling stability. The co-doped sample exhibits the optimal electrochemical performance due to the presence of appropriate Mn3+ content and higher Li+ ion diffusion coefficient.

scholarly journals Thermoelectric Generator Using Polyaniline-Coated Sb2Se3/β-Cu2Se Flexible Thermoelectric Films

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1518
Author(s):  
Minsu Kim ◽  
Dabin Park ◽  
Jooheon Kim
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Field Emission ◽  
Photoelectron Spectroscopy ◽  
Thermoelectric Generator ◽  
Hydrothermal Reaction ◽  
Water Evaporation ◽  
Pani Film ◽  
Portable Devices ◽  
X Ray

Herein, Sb2Se3 and β-Cu2Se nanowires are synthesized via hydrothermal reaction and water evaporation-induced self-assembly methods, respectively. The successful syntheses and morphologies of the Sb2Se3 and β-Cu2Se nanowires are confirmed via X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), and field emission transmission electron microscopy (FE-TEM). Sb2Se3 materials have low electrical conductivity which limits application to the thermoelectric generator. To improve the electrical conductivity of the Sb2Se3 and β-Cu2Se nanowires, polyaniline (PANI) is coated onto the surface and confirmed via Fourier-transform infrared spectroscopy (FT-IR), FE-TEM, and XPS analysis. After coating PANI, the electrical conductivities of Sb2Se3/β-Cu2Se/PANI composites were increased. The thermoelectric performance of the flexible Sb2Se3/β-Cu2Se/PANI films is then measured, and the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is shown to provide the highest power factor of 181.61 μW/m·K2 at 473 K. In addition, a thermoelectric generator consisting of five legs of the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is constructed and shown to provide an open-circuit voltage of 7.9 mV and an output power of 80.1 nW at ΔT = 30 K. This study demonstrates that the combination of inorganic thermoelectric materials and flexible polymers can generate power in wearable or portable devices.

Field-Emission Scanning Electron Microscopy and Energy-Dispersive X-Ray Analysis to Understand the Role of Tannin-Based Dyes in the Degradation of Historical Wool Textiles

2014 ◽  
Vol 20 (5) ◽  
pp. 1534-1543 ◽  
Author(s):  
Annalaura Restivo ◽  
Ilaria Degano ◽  
Erika Ribechini ◽  
Josefina Pérez-Arantegui ◽  
Maria Perla Colombini
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Elemental Composition ◽  
Field Emission ◽  
Cross Sections ◽  
Morphological Changes ◽  
Energy Dispersive ◽  
X Ray ◽  
Edx Analysis ◽  
Scanning Electron

Abstract:An innovative approach, combining field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDX) analysis, is presented to investigate the degradation mechanisms affecting tannin-dyed wool. In fact, tannin-dyed textiles are more sensitive to degradation then those dyed with other dyestuffs, even in the same conservation conditions.FESEM-EDX was first used to study a set of 48 wool specimens (artificially aged) dyed with several raw materials and mordants, and prepared according to historical dyeing recipes. EDX analysis was performed on the surface of wool threads and on their cross-sections. In addition, in order to validate the model formulated by the analysis of reference materials, several samples collected from historical and archaeological textiles were subjected to FESEM-EDX analysis.FESEM-EDX investigations enabled us to reveal the correlation between elemental composition and morphological changes. In addition, aging processes were clarified by studying changes in the elemental composition of wool from the protective cuticle to the fiber core in cross-sections. Morphological and elemental analysis of wool specimens and of archaeological and historical textiles showed that the presence of tannins increases wool damage, primarily by causing a sulfur decrease and fiber oxidation.

scholarly journals Nickel-Doped Cerium Oxide Nanoparticles: Green Synthesis Using Stevia and Protective Effect against Harmful Ultraviolet Rays

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4424 ◽  
Author(s):  
Mehrdad Khatami ◽  
Mina Sarani ◽  
Faride Mosazadeh ◽  
Mohammadreza Rajabalipour ◽  
Alireza Izadi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cerium Oxide ◽  
Field Emission ◽  
Cerium Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
Ni Doping ◽  
X Ray ◽  
Scanning Electron

Nanoparticles of cerium oxide CeO2 are important nanomaterials with remarkable properties for use in both industrial and non-industrial fields. In a general way, doping of oxide nanometric with transition metals improves the properties of nanoparticles. In this study, nickel- doped cerium oxide nanoparticles were synthesized from Stevia rebaudiana extract. Both doped and non-doped nanoparticles were characterized by X-ray diffraction, Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray, Raman spectroscopy, and Vibrating-Sample Magnetometry analysis. According to X-ray diffraction, Raman and Energy Dispersive X-ray crystalline and single phase of CeO2 and Ni doped CeO2 nanoparticles exhibiting fluorite structure with F2g mode were synthesized. Field Emission Scanning Electron Microscopy shows that CeO2 and Ni doped nanoparticles have spherical shape and sizes ranging of 8 to 10 nm. Ni doping of CeO2 results in an increasing of magnetic properties. The enhancement of ultraviolet protector character via Ni doping of CeO2 is also discussed.

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.

Facile Synthesis of Tremella-Like Li3V2(PO4)3/C Composite Cathode Materials Based on Oroxylum for Use in Lithium-Ion Batteries

2020 ◽  
Vol 20 (3) ◽  
pp. 1962-1967
Author(s):  
Zhen Liu ◽  
Wei Zhou ◽  
Guilin Zeng ◽  
Yuling Zhang ◽  
Zebin Wu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cathode Materials ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Composite Cathode ◽  
Potential Range ◽  
X Ray Diffraction ◽  
Immersion Method ◽  
X Ray ◽  
Transmission Electron

Oroxylum as a traditional Chinese medicine, was used as a green and novel bio-template to synthesize tremella-like Li3V2(PO4)3/C composite (LVPC) cathode materials by adopting a facile immersion method. The microstructures were analyzed by X-ray diffraction analysis, scanning electron microscopy, and transmission electron microscopy. The electrochemical properties were investigated by galvanostatic charge–discharge experiments. The LVPC revealed specific capacity of 95 mAh·g-1 at 1 C rate within potential range of 3.0–4.3 V. After 100 cycles at 0.2 C, the retention of discharge capacity was 96%. The modified electrochemical performance is mainly resulted from the distinct tremella-like structure.

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