scholarly journals Doping and Surface Modification Enhance the Applicability of Nanostructured Fullerene-MWCNT Hybrid Draped LiNi0.1Mg0.1Co0.8O2 As High Efficient Cathode Material for Lithium-Ion Batteries

2021 ◽  
Author(s):  
Arockia Shyamala Paniyarasi S ◽  
Suja S K ◽  
Nimma Elizabeth R
Keyword(s):  
Electron Microscopy ◽  
Diffusion Coefficient ◽  
Surface Modification ◽  
Electrochemical Performance ◽  
Cathode Material ◽  
Structural Stability ◽  
Cathode Materials ◽  
Transfer Resistance ◽  
X Ray ◽  
High Efficient

Abstract Development of high performance cathode materials, layer-structured ternary LiNi x Co y M 1-x-y O 2 cathode materials have attracted much attention owing to their larger capacity and higher energy density.Persistent efforts have been devoted to tackling certain issues like low electronic conductivity and poor structural stability. Dual strategy of Mg doping and surface modification of the cathode material was adopted to improve the performance of the battery. Fullerene-Multi-Walled Carbon Nanotube (MWCNT) hybrid draped LiNi 0.1 Mg 0.1 Co 0.8 O 2 nanocomposite was synthesized by a simple chemical route. The fullerene-MWCNT hybrid modifies the surface of pristine LiNi 0.1 Mg 0.1 Co 0.8 O 2 thereby improves the electrochemical performance and maintains the structural stability of the cathode material. Pristine LiNi 0.1 Mg 0.1 Co 0.8 O 2 and LiNi 0.1 Mg 0.1 Co 0.8 O 2 / fullerene-MWCNT nanocomposite were studied using various advanced characterization techniques such as X-ray diffraction (XRD), Micro-Raman spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), X-ray Photoelectron Spectroscopy (XPS), and High-Resolution Transmission Electron Microscopy (HRTEM). It is found that LiNi 0.1 Mg 0.1 Co 0.8 O 2 particles retain their structural integrity after being enveloped with a fullerene-MWCNT hybrid. The electrochemical performance was investigated with cyclic voltammetry(CV), galvanostaticcharge-discharge(GCD) test and electrochemical impedance spectroscopy(EIS). As prepared LiNi 0.1 Mg 0.1 Co 0.8 O 2 , when deployed in the form of LiNi 0.1 Mg 0.1 Co 0.8 O 2 / fullerene-MWCNT composite exhibits a high specific capacity of 208 mAh g -1 .Fullerene-MWCNT hybrid draped LiNi 0.1 Mg 0.1 Co 0.8 O 2 nanocomposite provides an effective Li + and electron channel that significantly increased the Li-ion diffusion coefficient and reduced the charge transfer resistance. Besides,the lithium diffusion coefficient increased from 5.13 x 10 -13 (Li/LiNi 0.1 Mg 0.1 Co 0.8 O 2 ) to 8.313 x 10 -13 cm 2 s -1 due to the improved kinetics of Li insertion/extraction process in Li/LiNi 0.1 Mg 0.1 Co 0.8 O 2 +fullerene-MWCNT cell.

Concentration-Controlled and Phytic Acid-Assisted Synthesis of Self-Assembled LiFePO4 as Cathode Materials for Lithium-Ion Battery

NANO ◽  
2020 ◽  
Vol 15 (01) ◽  
pp. 2050003
Author(s):  
Yin Li ◽  
Keyu Zhang ◽  
Zhengjie Chen ◽  
Yunke Wang ◽  
Li Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Diffusion Coefficient ◽  
Electrochemical Performance ◽  
Phytic Acid ◽  
Cathode Materials ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Precursor Concentration ◽  
Phosphorus Source ◽  
Self Assembled

The olivine LiFePO4 with various morphologies and different growth lattice planes was prepared by a controllable hydrothermal method with changing precursor concentration and using phytic acid as phosphorus source. The microstructure, crystal orientation and electrochemical performance of the prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and charge–discharge tests. The results show that the morphologies of all samples change from spindle-like to hierarchical plate-like and then to long plate-like shape, and the main exposed facets transform from (100) to (001). This indicates that the precursor concentration and phytic acid play important roles in exposing facets and controlling the morphology of LiFePO4. In order to illustrate these phenomena, a reasonable assembly process is provided and the formation is explained. Li ion diffusion coefficient along [100] and [001] directions was calculated by using electrochemical impedance spectroscopy (EIS). The results show that the diffusion coefficient of (100) facet is higher than that of (001) facet, indicating a good electrochemical performance for (100) facet. In addition, the capacity test is carried out, which also confirms the above results. With the precursor concentration of 0.5[Formula: see text]M, the obtained LiFePO4 with self-assembled hierarchical structure, smaller size and (100) facet shows the best electrochemical performance: 162.1[Formula: see text]mAh/g at 0.1[Formula: see text]C and 112.4[Formula: see text]mAh/g at 10[Formula: see text]C. Using phytic acid as phosphorus source and controlling precursor concentration to prepare high performance LiFePO4 open up a new prospect for the production of cathode materials for lithium ion batteries.

scholarly journals Enhancement of the Electrochemical Performance of LiNi1/3Co1/3Mn1/3O2 Cathode Material by Double-Layer Coating with Graphene Oxide and SnO2 for Lithium-Ion Batteries

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Yuxin Ma ◽  
Ping Cui ◽  
Dan Zhan ◽  
Bing Gan ◽  
Youliang Ma ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Cathode Material ◽  
Electrochemical Impedance ◽  
Coating Layer ◽  
Rate Capability ◽  
Electrode Polarization ◽  
Transfer Resistance ◽  
X Ray ◽  
Double Coating

The graphene oxide-coated SnO2-Li1/3Co1/3Mn1/3O2 (GO-SnO2-NCM) cathode material was successfully synthesized via a facile wet chemical method. The pristine NCM and GO-SnO2-NCM were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The results showed that the double-coating layer did not destroy the NCM crystal structure, with multiple nano-SnO2 particles and GO uniformly covering the NCM surface. Electrochemical tests indicated that GO-SnO2-NCM exhibited excellent cycling performance, with 90.7% capacity retention at 1 C after 100 cycles, which was higher than 74.3% for the pristine NCM at the same cycle. The rate capability showed that the double-coating layer enhanced surface electronic–ionic transport. Electrochemical impedance spectroscopy results confirmed that the GO-SnO2-coating layer effectively suppressed the increased electrode polarization and charge transfer resistance during cycling.

scholarly journals Improved Electrochemical Performance of 0.5Li2MnO3·0.5LiNi0.5Mn0.5O2 Cathode Materials for Lithium Ion Batteries Synthesized by Ionic-Liquid-Assisted Hydrothermal Method

2020 ◽  
Vol 8 ◽  
Author(s):  
Yanhong Xiang ◽  
Youliang Jiang ◽  
Saiqiu Liu ◽  
Jianhua Wu ◽  
Zhixiong Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ionic Liquid ◽  
Electrochemical Performance ◽  
Hydrothermal Method ◽  
Cathode Materials ◽  
Electrochemical Impedance ◽  
Rate Capability ◽  
Lithium Ion ◽  
Charge Transfer Resistance ◽  
Transfer Resistance

Well-dispersed Li-rich Mn-based 0.5Li2MnO3·0.5LiNi0.5Mn0.5O2 nanoparticles with diameter ranging from 50 to 100 nm are synthesized by a hydrothermal method in the presence of N-hexyl pyridinium tetrafluoroborate ionic liquid ([HPy][BF4]). The microstructures and electrochemical performance of the prepared cathode materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electrochemical measurements. The XRD results show that the sample prepared by ionic-liquid-assisted hydrothermal method exhibits a typical Li-rich Mn-based pure phase and lower cation mixing. SEM and TEM images indicate that the extent of particle agglomeration of the ionic-liquid-assisted sample is lower compared to the traditional hydrothermal sample. Electrochemical test results indicate that the materials synthesized by ionic-liquid-assisted hydrothermal method exhibit better rate capability and cyclability. Besides, electrochemical impedance spectroscopy (EIS) results suggest that the charge transfer resistance of 0.5Li2MnO3· 0.5LiNi0.5Mn0.5O2 synthesized by ionic-liquid-assisted hydrothermal method is much lower, which enhances the reaction kinetics.

Effect of Nano TiO2 Coating on Electrochemical Performance of the Li1.2Mn0.6Ni0.2O2 Cathode Materials

2014 ◽  
Vol 1035 ◽  
pp. 361-365 ◽  
Author(s):  
Jian Chen LI ◽  
Sheng Li Pang ◽  
Xiang Qian Shen ◽  
Xiao Ming Xi ◽  
Da Qian Liao
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Performance ◽  
Cathode Material ◽  
Electrochemical Techniques ◽  
Cycling Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Surface ◽  
Bulk Structure

In this paper, a Li-rich cathode material Li1.2Mn0.6Ni0.2O2is modified by the nanoscale TiO2coating using a simple and controllable hydrolyzation method. The effect of nanoscale TiO2coating on the bulk structure, surface morphology and electrochemical performance are characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and electrochemical techniques, respectively. The results show that the nanosize TiO2can be well coated on the surface of the cathode material. The coating layers have no influence on the bulk structure of the cathode material, while they can improve the initial discharge capacity, columbic efficiency and cycling performance.

Hydrothermal Synthesis and Electrochemical Performance of WO3 Nanoparticles

2013 ◽  
Vol 750-752 ◽  
pp. 217-220
Author(s):  
Li Jin Feng ◽  
Rong Ma ◽  
Xiu Hua Li ◽  
Xu Chun Song
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cyclic Voltammetry ◽  
Hydrothermal Synthesis ◽  
Electrochemical Performance ◽  
Electrochemical Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrogen Intercalation ◽  
Transmission Electron

In the present paper, the WO3 nanoparticles were fabricated via a hydrothermal treatment. The products are characterized in detail by multiform techniques: transmission electron microscopy, X-ray diffraction. The results show that products are WO3 nanoparticles with diameter of about 100-150 nm. Electrochemistry properties of the prepared WO3 nanoparticles was characterized by cyclic voltammetry. Cyclic voltammetry results indicate that WO3 nanoparticles exhibits a remarkable electrochemical activity for hydrogen intercalation. The reason for electrochemical activity of WO3 nanoparticles is attributed to the formation of HxWO3 by hydrogen intercalation/de-intercalation into/out of the tungsten oxide.

Improved structural stability and electrochemical performance of Na3V2 (PO4)3 cathode material by Cr doping

Ionics ◽  
2016 ◽  
Vol 23 (5) ◽  
pp. 1097-1105 ◽  
Author(s):  
Yanli Ruan ◽  
Kun Wang ◽  
Shidong Song ◽  
Jingjing Liu ◽  
Xu Han
Keyword(s):  
Electrochemical Performance ◽  
Cathode Material ◽  
Structural Stability ◽  
Cr Doping

scholarly journals Surface Functionalization of Three Dimensional-Printed Polycaprolactone-Bioactive Glass Scaffolds by Grafting GelMA Under UV Irradiation

2020 ◽  
Vol 7 ◽  
Author(s):  
Farnaz Ghorbani ◽  
Melika Sahranavard ◽  
Zohre Mousavi Nejad ◽  
Dejian Li ◽  
Ali Zamanian ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Roughness ◽  
Surface Modification ◽  
Bioactive Glass ◽  
Uv Irradiation ◽  
Three Dimensional ◽  
Homogeneous Distribution ◽  
X Ray ◽  
Fused Deposition ◽  
3D Printed

In this study, bioactive glass nanoparticles (BGNPs) with an average diameter of less than 10 nm were synthesized using a sol-gel method and then characterized by transmission electron microscopy (TEM), differential scanning calorimetric (DSC), Fourier transforms infrared spectroscopy (FTIR), and x-ray spectroscopy (XRD). Afterward, three dimensional (3D)-printed polycaprolactone (PCL) scaffolds along with fused deposition modeling (FDM) were incorporated with BGNPs, and the surface of the composite constructs was then functionalized by coating with the gelatin methacryloyl (GelMA) under UV irradiation. Field emission scanning electron microscopy micrographs demonstrated the interconnected porous microstructure with an average pore diameter of 260 µm and homogeneous distribution of BGNPs. Therefore, no noticeable shrinkage was observed in 3D-printed scaffolds compared with the computer-designed file. Besides, the surface was uniformly covered by GelMA, and no effect of surface modification was observed on the microstructure while surface roughness increased. The addition of the BGNPs the to PCL scaffolds showed a slight change in pore size and porosity; however, it increased surface roughness. According to mechanical analysis, the compression strength of the scaffolds was increased by the BGNPs addition and surface modification. Also, a reduction was observed in the absorption capacity and biodegradation of scaffolds in phosphate-buffered saline media after the incorporation of BGNPs, while the presence of the GelMA layer increased the swelling potential and stability of the composite matrixes. Moreover, the capability of inducing bio-mineralization of hydroxyapatite-like layers, as a function of BGNPs content, was proven by FE-SEM micrographs, EDX spectra, and x-ray diffraction spectra (XRD) after soaking the obtained samples in concentrated simulated body fluid. A higher potential of the modified constructs to interact with the aqueous media led to better precipitation of minerals. According to in-vitro assays, the modified scaffolds can provide a suitable surface for the attachment and spreading of the bone marrow mesenchymal stem cells (BMSCs). Furthermore, the number of the proliferated cells confirms the biocompatibility of the scaffolds, especially after a modification process. Cell differentiation was verified by alkaline phosphatase activity as well as the expression of osteogenic genes such as osteocalcin and osteopontin. Accordingly, the scaffolds showed an initial potential for reconstruction of the injured bone.

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