scholarly journals SiO2 Coated Li-rich Layered Oxides-Li1.2Ni0.13Mn0.54Co0.13O2 for efficient energy storage applications

2020 ◽  
Author(s):  
Jeffin James Abraham ◽  
Umair Nisar ◽  
Haya Monawwar ◽  
Aisha Abdul Quddus ◽  
Abdul Shakoor ◽  
...  
Keyword(s):  
Energy Storage ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Lithium Ion ◽  
Side Reactions ◽  
Electrochemical Performances ◽  
Layered Oxides ◽  
Capacity Retention ◽  
Pure Material ◽  
X Ray

Lithium ion batteries (LIBs) are attractive for energy storage application. In this regard, lithium rich layered oxides (LLOs), are considered viable cathodes due to their tempting properties such as lower production cost, faster manufacturing process, excellent reversible capacity, and better electrochemical performance at high voltages. Despite these properties, LLOs lack in cyclic stability and inferior capacity retention. This study proposes a surface modification technique to overcome the above-mentioned limitations in which a layer of silica (SiO2) has been coated on the particles of Li1.2Ni0.13Mn0.54Co0.13O2. The Li1.2Ni0.13Mn0.54Co0.13O2 was synthesized by a sol-gel process and then coated with SiO2 (SiO2=1.0 wt. %, 1.5 wt. %, and 2.0 wt. %). The coatings were undertaken through a dry ball milling technique. Different characterization test such as X-Ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), elemental mapping, and X-ray photoelectron spectroscopy (XPS), were utilized to prove phase pure material formation and identify the SiO2 layer on the surface of Li1.2Ni0.13Mn0.54Co0.13O2. The electrochemical measurements, confirm the improvement in capacity retention and cyclability of SiO2 coated Li1.2Ni0.13Mn0.54Co0.13O2 samples with reference to the uncoated samples. This improvement can be ascribed to the protective and barrier effect of the coated layer on the LLOs particles avoiding any unwanted side reactions when the cathode is exposed to the electrolyte. A small trade-off between electrochemical performances and the coating thickness confirms the best efficiency of 1 wt.% SiO2 coated Li1.2Ni0.13Mn0.54Co0.13O2 when compared to other coated samples.

scholarly journals Improved electrochemical performance of SiO2-coated Li-rich layered oxides-Li1.2Ni0.13Mn0.54Co0.13O2

2020 ◽  
Vol 31 (21) ◽  
pp. 19475-19486
Author(s):  
Jeffin James Abraham ◽  
Umair Nisar ◽  
Haya Monawwar ◽  
Aisha Abdul Quddus ◽  
R. A. Shakoor ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Cathode Material ◽  
Sol Gel ◽  
Rate Capability ◽  
Lithium Ion ◽  
Side Reactions ◽  
Operating Voltage ◽  
Layered Oxides ◽  
Capacity Retention ◽  
Xps Characterization

AbstractLithium-rich layered oxides (LLOs) such as Li1.2Ni0.13Mn0.54Co0.13O2 are suitable cathode materials for future lithium-ion batteries (LIBs). Despite some salient advantages, like low cost, ease of fabrication, high capacity, and higher operating voltage, these materials suffer from low cyclic stability and poor capacity retention. Several different techniques have been proposed to address the limitations associated with LLOs. Herein, we report the surface modification of Li1.2Ni0.13Mn0.54Co0.13O2 by utilizing cheap and readily available silica (SiO2) to improve its electrochemical performance. Towards this direction, Li1.2Ni0.13Mn0.54Co0.13O2 was synthesized utilizing a sol–gel process and coated with SiO2 (SiO2 = 1.0 wt%, 1.5 wt%, and 2.0 wt%) employing dry ball milling technique. XRD, SEM, TEM, elemental mapping and XPS characterization techniques confirm the formation of phase pure materials and presence of SiO2 coating layer on the surface of Li1.2Ni0.13Mn0.54Co0.13O2 particles. The electrochemical measurements indicate that the SiO2-coated Li1.2Ni0.13Mn0.54Co0.13O2 materials show improved electrochemical performance in terms of capacity retention and cyclability when compared to the uncoated material. This improvement in electrochemical performance can be related to the prevention of electrolyte decomposition when in direct contact with the surface of charged Li1.2Ni0.13Mn0.54Co0.13O2 cathode material. The SiO2 coating thus prevents the unwanted side reactions between cathode material and the electrolyte. 1.0 wt% SiO2-coated Li1.2Ni0.13Mn0.54Co0.13O2shows the best electrochemical performance in terms of rate capability and capacity retention.

scholarly journals Microwave synthesis of high-quality and uniform 4 nm ZnFe2O4 nanocrystals for application in energy storage and nanomagnetics

2016 ◽  
Vol 7 ◽  
pp. 1350-1360 ◽  
Author(s):  
Christian Suchomski ◽  
Ben Breitung ◽  
Ralf Witte ◽  
Michael Knapp ◽  
Sondes Bauer ◽  
...  
Keyword(s):  
Energy Storage ◽  
Photoelectron Spectroscopy ◽  
Zinc Ferrite ◽  
Sol Gel ◽  
High Capacity ◽  
Spherical Shape ◽  
Freezing Temperature ◽  
Ex Situ ◽  
Edge Structure ◽  
X Ray

Magnetic nanocrystals with a narrow size distribution hold promise for many applications in different areas ranging from biomedicine to electronics and energy storage. Herein, the microwave-assisted sol–gel synthesis and thorough characterization of size-monodisperse zinc ferrite nanoparticles of spherical shape is reported. X-ray diffraction, 57Fe Mössbauer spectroscopy and X-ray photoelectron spectroscopy all show that the material is both chemically and phase-pure and adopts a partially inverted spinel structure with Fe3+ ions residing on tetrahedral and octahedral sites according to (Zn0.32Fe0.68)tet[Zn0.68Fe1.32]octO4±δ. Electron microscopy and direct-current magnetometry confirm the size uniformity of the nanocrystals, while frequency-dependent alternating-current magnetic susceptibility measurements indicate the presence of a superspin glass state with a freezing temperature of about 22 K. Furthermore, as demonstrated by galvanostatic charge–discharge tests and ex situ X-ray absorption near edge structure spectroscopy, the as-prepared zinc ferrite nanocrystals can be used as a high-capacity anode material for Li-ion batteries, showing little capacity fade – after activation – over hundreds of cycles. Overall, in addition to the good material characteristics, it is remarkable that the microwave-based synthetic route is simple, easily reproducible and scalable.

scholarly journals Electrochemical Performance of Nitrogen-Doped TiO2 Nanotubes as Electrode Material for Supercapacitor and Li-Ion Battery

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2952 ◽  
Author(s):  
Tamilselvan Appadurai ◽  
Chandrasekar Subramaniyam ◽  
Rajesh Kuppusamy ◽  
Smagul Karazhanov ◽  
Balakumar Subramanian
Keyword(s):  
Energy Storage ◽  
Electrochemical Performance ◽  
Electrode Material ◽  
Photoelectron Spectroscopy ◽  
Tio2 Nanotubes ◽  
Lithium Ion ◽  
Great Promise ◽  
Electrochemical Performances ◽  
Doped Tio2 ◽  
Nitrogen Doped

Electrochemical anodized titanium dioxide (TiO2) nanotubes are of immense significance as electrochemical energy storage devices owing to their fast electron transfer by reducing the diffusion path and paving way to fabricating binder-free and carbon-free electrodes. Besides these advantages, when nitrogen is doped into its lattice, doubles its electrochemical activity due to enhanced charge transfer induced by oxygen vacancy. Herein, we synthesized nitrogen-doped TiO2 (N-TiO2) and studied its electrochemical performances in supercapacitor and as anode for a lithium-ion battery (LIB). Nitrogen doping into TiO2 was confirmed by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) techniques. The electrochemical performance of N-TiO2 nanotubes was outstanding with a specific capacitance of 835 µF cm−2 at 100 mV s−1 scan rate as a supercapacitor electrode, and it delivered an areal discharge capacity of 975 µA h cm−2 as an anode material for LIB which is far superior to bare TiO2 nanotubes (505 µF cm−2 and 86 µA h cm−2, respectively). This tailor-made nitrogen-doped nanostructured electrode offers great promise as next-generation energy storage electrode material.

scholarly journals Microencapsulation of stearic acid with SiO2 shell as phase change material for potential energy storage

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shafiq Ishak ◽  
Soumen Mandal ◽  
Han-Seung Lee ◽  
Jitendra Kumar Singh
Keyword(s):  
Energy Storage ◽  
Stearic Acid ◽  
Phase Change ◽  
Phase Change Material ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Sio2 Shell ◽  
Change Material

Abstract Stearic acid (SA) is being used as phase change material (PCM) in energy storage applications. In the present study, the microencapsulation of SA with SiO2 shell was carried out by sol–gel method. Different amounts of SA (5, 10, 15, 20, 30 and 50 g) were taken against 10 ml of tetraethyl orthosilicate (TEOS) for encapsulation. The synthesized microencapsulated PCM (MEPCM) were characterized by Fourier transform infrared spectroscope (FT-IR), X-Ray diffraction (XRD), X-Ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The characterization results showed that SA was successfully encapsulated by SiO2. Thermogravimetric analysis (TGA) exhibited better thermal stability of the MEPCM than SA. The enthalpy values of MEPCM were found to be unchanged even after 30 heating–cooling cycles by differential scanning calorimetry (DSC). The latent heats of melting and solidification of 50 g SA containing MEPCM were found to be highest i.e. 182.53 J/g and 160.12 J/g, respectively among all microencapsulated samples. The encapsulation efficiency values were calculated using thermal data and the efficiency was found to be highest i.e. 86.68% in the same sample.

scholarly journals Preparation of LiFePO4/C Cathode Materials via a Green Synthesis Route for Lithium-Ion Battery Applications

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2251 ◽  
Author(s):  
Rongyue Liu ◽  
Jianjun Chen ◽  
Zhiwen Li ◽  
Qing Ding ◽  
Xiaoshuai An ◽  
...  
Keyword(s):  
Cathode Materials ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Lithium Ion ◽  
Lithium Carbonate ◽  
Electrochemical Performances ◽  
Scanning Calorimetry ◽  
Xps Spectra ◽  
X Ray ◽  
Exhaust Purification

In this work, LiFePO4/C composite were synthesized via a green route by using Iron (III) oxide (Fe2O3) nanoparticles, Lithium carbonate (Li2CO3), glucose powder and phosphoric acid (H3PO4) solution as raw materials. The reaction principles for the synthesis of LiFePO4/C composite were analyzed, suggesting that almost no wastewater and air polluted gases are discharged into the environment. The morphological, structural and compositional properties of the LiFePO4/C composite were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), Raman and X-ray photoelectron spectroscopy (XPS) spectra coupled with thermogravimetry/Differential scanning calorimetry (TG/DSC) thermal analysis in detail. Lithium-ion batteries using such LiFePO4/C composite as cathode materials, where the loading level is 2.2 mg/cm2, exhibited excellent electrochemical performances, with a discharge capability of 161 mA h/g at 0.1 C, 119 mA h/g at 10 C and 93 mA h/g at 20 C, and a cycling stability with 98.0% capacity retention at 1 C after 100 cycles and 95.1% at 5 C after 200 cycles. These results provide a valuable approach to reduce the manufacturing costs of LiFePO4/C cathode materials due to the reduced process for the polluted exhaust purification and wastewater treatment.

scholarly journals Effects of Palladium Doping on the Structure and Electrochemical Properties of LiFePO4/C Prepared using the Sol-gel Method

2014 ◽  
Vol 17 (2) ◽  
pp. 091-097 ◽  
Author(s):  
M. Talebi-Esfandarani ◽  
O. Savadogo
Keyword(s):  
Electrochemical Properties ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Lithium Ion ◽  
Lattice Parameters ◽  
Area Measurement ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Palladium Doping

LiFePO4/C, LiFe0.98Pd0.02PO4/C, and LiFe0.96Pd0.04PO4/C composite cathode materials were synthesized using the sol-gel method. The effect of palladium on the structure and electrochemical properties of LiFePO4/C have been investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), surface area measurement (BET), charge/discharge testing, and cyclic voltammetry (CV). The results indicate that palladium doping facilitates the formation of impurities, like Li3PO4. Also, the lattice parameters of the LiFePO4 structure decrease in size as the palladium content increases. In addition, the particles become larger and agglomerated by palladium incorporation. The electrochemical results show that palladium doping decreases the electrochemical performance of LiFePO4/C, owing to shrinking lattice parameters and the difficulty of achieving the diffusion of lithium ions into the structure during the intercalation/de-intercalation process. These results suggest that palladium doping by sol-gel method changes significantly the LiFePO4 structure which may impact it performances as cathode for the lithium ion battery applications.

scholarly journals Electrochemical study on nickel aluminum layered double hydroxides as high-performance electrode material for lithium-ion batteries based on sodium alginate binder

2021 ◽  
Author(s):  
Xinyue Li ◽  
Marco Fortunato ◽  
Anna Maria Cardinale ◽  
Angelina Sarapulova ◽  
Christian Njel ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Electrode Material ◽  
Photoelectron Spectroscopy ◽  
Negative Electrode ◽  
Lithium Ion ◽  
Electrochemical Study ◽  
Ex Situ ◽  
Potential Range ◽  
X Ray ◽  
Storage Mechanism

AbstractNickel aluminum layered double hydroxide (NiAl LDH) with nitrate in its interlayer is investigated as a negative electrode material for lithium-ion batteries (LIBs). The effect of the potential range (i.e., 0.01–3.0 V and 0.4–3.0 V vs. Li+/Li) and of the binder on the performance of the material is investigated in 1 M LiPF6 in EC/DMC vs. Li. The NiAl LDH electrode based on sodium alginate (SA) binder shows a high initial discharge specific capacity of 2586 mAh g−1 at 0.05 A g−1 and good stability in the potential range of 0.01–3.0 V vs. Li+/Li, which is better than what obtained with a polyvinylidene difluoride (PVDF)-based electrode. The NiAl LDH electrode with SA binder shows, after 400 cycles at 0.5 A g−1, a cycling retention of 42.2% with a capacity of 697 mAh g−1 and at a high current density of 1.0 A g−1 shows a retention of 27.6% with a capacity of 388 mAh g−1 over 1400 cycles. In the same conditions, the PVDF-based electrode retains only 15.6% with a capacity of 182 mAh g−1 and 8.5% with a capacity of 121 mAh g−1, respectively. Ex situ X-ray photoelectron spectroscopy (XPS) and ex situ X-ray absorption spectroscopy (XAS) reveal a conversion reaction mechanism during Li+ insertion into the NiAl LDH material. X-ray diffraction (XRD) and XPS have been combined with the electrochemical study to understand the effect of different cutoff potentials on the Li-ion storage mechanism. Graphical abstract The as-prepared NiAl-NO3−-LDH with the rhombohedral R-3 m space group is investigated as a negative electrode material for lithium-ion batteries (LIBs). The effect of the potential range (i.e., 0.01–3.0 V and 0.4–3.0 V vs. Li+/Li) and of the binder on the material’s performance is investigated in 1 M LiPF6 in EC/DMC vs. Li. Ex situ X-ray photoelectron spectroscopy (XPS) and ex situ X-ray absorption spectroscopy (XAS) reveal a conversion reaction mechanism during Li+ insertion into the NiAl LDH material. X-ray diffraction (XRD) and XPS have been combined with the electrochemical study to understand the effect of different cutoff potentials on the Li-ion storage mechanism. This work highlights the possibility of the direct application of NiAl LDH materials as negative electrodes for LIBs.

scholarly journals Enhanced Photocatalytic Activity of CuWO4 Doped TiO2 Photocatalyst Towards Carbamazepine Removal under UV Irradiation

Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 25
Author(s):  
Chukwuka Bethel Anucha ◽  
Ilknur Altin ◽  
Emin Bacaksız ◽  
Tayfur Kucukomeroglu ◽  
Masho Hilawie Belay ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Pure Tio2 ◽  
Component Part ◽  
Energy Yield ◽  
Mechanical Agitation ◽  
X Ray

Abatement of contaminants of emerging concerns (CECs) in water sources has been widely studied employing TiO2 based heterogeneous photocatalysis. However, low quantum energy yield among other limitations of titania has led to its modification with other semiconductor materials for improved photocatalytic activity. In this work, a 0.05 wt.% CuWO4 over TiO2 was prepared as a powder composite. Each component part synthesized via the sol-gel method for TiO2, and CuWO4 by co-precipitation assisted hydrothermal method from precursor salts, underwent gentle mechanical agitation. Homogenization of the nanopowder precursors was performed by zirconia ball milling for 2 h. The final material was obtained after annealing at 500 °C for 3.5 h. Structural and morphological characterization of the synthesized material has been achieved employing X-ray diffraction (XRD), Fourier transform infra-red (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) N2 adsorption–desorption analysis, Scanning electron microscopy-coupled Energy dispersive X-ray spectroscopy (SEM-EDS), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectroscopy (UV-vis DRS) for optical characterization. The 0.05 wt.% CuWO4-TiO2 catalyst was investigated for its photocatalytic activity over carbamazepine (CBZ), achieving a degradation of almost 100% after 2 h irradiation. A comparison with pure TiO2 prepared under those same conditions was made. The effect of pH, chemical scavengers, H2O2 as well as contaminant ion effects (anions, cations), and humic acid (HA) was investigated, and their related influences on the photocatalyst efficiency towards CBZ degradation highlighted accordingly.

scholarly journals Synthesis, characterization and in vitro cytotoxicity study of Co and Ni ferrite nanoparticles prepared by sol-gel method

2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Alexandre Pancotti ◽  
Dener Pereira Santos ◽  
Dielly Oliveira Morais ◽  
Mauro Vinícius de Barros Souza ◽  
Débora R. Lima ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Test Sample ◽  
In Vitro Cytotoxicity ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Crystallite Sizes

AbstractIn this study, we report the synthesis and characterization of NiFe2O4 and CoFe2O4 nanoparticles (NPs) which are widely used in the biomedical area. There is still limited knowledge how the properties of these materials are influenced by different chemical routes. In this work, we investigated the effect of heat treatment over cytotoxicity of cobalt and niquel ferrites NPs synthesized by sol-gel method. Then the samples were studied using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), Fourier Transform Infrared Spectroscopy Analysis (FTIR), and X-ray fluorescence (XRF). The average crystallite sizes of the particles were found to be in the range of 20–35 nm. The hemocompatibility (erythrocytes and leukocytes) was checked. Cytotoxicity results were similar to those of the control test sample, therefore suggesting hemocompatibility of the tested materials.

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