الفهرس 
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Abstract
study of some nanomaterials as a potential electrode for rechargeable Li-ion batteries
A Thesis Submitted to Faculty of Science-Ain Shams University in partial fulfillment for The Degree of master of Science (M.Sc.) in Physics
By
Menna-Allah Mahmoud Ghannam
B.Sc. in Materials Physics - Faculty of Science- Ain Shams University-2015
Supervised by
Prof. Dr. Zein El-Abidin Kamel Heiba
Professor of Material Physics
Physics Department, Faculty of Science-ASU
Prof. Dr. Ali Abd-El Rahman Abou Shama
Professor of Materials Science
Physics Department, Faculty of Science-ASU
Assoc. Prof. Dr. Mustafa Mohamed Saad Sanad
Assoc. Prof. of Chemical and
Electrometallurgy Division
Central Metallurgical Research and Development Center
Physics Department
Faculty of Science
Ain Shams University
2021
APPROVAL SHEET
study of some nanomaterials as a potential electrode for rechargeable Li-ion batteries
By
Menna-Allah Mahmoud Ghannam
Supervisors Signature
Prof. Dr. Zein El-Abidin Kamel Heiba ………………….
Professor of Material Physics
Physics Department, Faculty of Science-ASU
Prof. Dr. Ali Abd-El Rahman Abou Shama ………………….
Professor of Materials Science
Physics Department, Faculty of Science-ASU
Assoc. Prof. Mustafa Mohamed Saad Sanad ………………….
Assoc. Prof. of Chemical and Electrometallurgy Division
Central Metallurgical Research and Development Center
2021
Ain Shams University
Study of some nanomaterials as a potential electrode for rechargeable Li-ion batteries
Name: Menna-Allah Mahmoud Ghannam
Degree: M. Sc.
Department: Physics
Faculty: Science
University: Ain Shams University
Graduation Date: 2015- Ain Shams University
Registration Date: 11/3/2019
Grant Year:2021
© 2021
Menna-Allah Mahmoud Ghannam
ALL RIGHTS RESERVED
ACKNOWLEDGEMENT
First, thanks to God the most, the most gracious, who gave me the capabilities to complete this work.
I am grateful to express my special appreciation and thanks to my supervisors for their continuous support, experienced advice, and great assistance. It was a great honor to work under their guidance and supervision.
I would like to extend my deep thanks to my supervisor Prof. Dr. Zein El-Abidin Heiba who has established the principles of scientific research in my mind and helped me to stand on a strong basis in the field of solid-state physics. He provided continuous support and fruitful assistance to complete this work.
I also extend my warm thanks to my supervisor Prof. Dr. Mustafa Sanad who supported me with his time, effort, and sincere guidance. He has always provided me with his inspiring scientific advice that helped to complete this work and preparing the thesis.
My sincere thanks are presented to my supervisor Prof. Dr. Ali Aboshama prof. of Physics Department, Faculty of Science, Ain-Shams University, for his kind supervision.
Besides my supervisors, I would like to thank our lab unit colleagues Prof. Dr. Mohamed Bakr, Prof. Dr. Sameh Ibrahim, Dr. Hassan El-Shemi, and Noura Mohamed and Dr. Mahmoud Abdellatif from SESAME for their great assistance. I would like to thank Dr. Ahmed Abd El-Aziz, Neaama, and Shadia from Metallurgical research center for their great assistant and helpful comments.
I would like to extend my sincere thanks to those all I have in this life, my family, who I give credit to after God for what I am now. They strongly believed in me and gave me their continued support.
Finally, I would like to gratitude Electrochemical unit header and staff members at Metallurgical research center to give me a chance to work in their laboratories.
Published papers
• Ghannam M. M., Heiba Z. K., Sanad M. M. S., & Mohamed M. B. (2020). Functional properties of ZnMn2O4/MWCNT/graphene nanocomposite as anode material for Li-ion batteries. Applied Physics A, 126(5) (2020) 1-9.
• Heiba Z. K., Ghannam M. M., Sanad M. M. S., Albassam A. A., & Mohamed, M. B. (2020). Structural, optical, and dielectric properties of nano-ZnMn2−xVxO4. Journal of Materials Science: Materials in Electronics, 31(11) (2020) 8946-8962.
Table of Contents:
List of Figures iv
List of Tables viii
List of Abbreviations ix
List of Symbols x
ABSTRACT xi
CHAPTER 1: INTRODUCTION AND LITERATURE REVIEW 1
1.1 Introduction 1
1.1.1 Motivation 1
1.1.2 Goal of this work 2
1.2 Literature review 4
1.2.1 ZnMn2O4 as a promising material for LIBs 4
1.2.2 ZnMn2O4 with carbon additives 6
1.2.3 Vanadium oxides in LIBs 7
CHAPTER 2: THEORETICAL BACKGROUND 9
2.1 Structure and microstructure analysis 9
2.1.1 Rietveld method 9
2.2 Dielectric analysis 14
2.2.1 Complex impedance technique 14
2.2.2 Normal and relaxor ferroelectric materials 15
2.3 Electrochemical testing performance 18
2.3.1 Cell potential 18
2.3.2 Specific capacity 19
2.3.3 Rate capability 19
2.3.4 Irreversible capacity 20
2.3.5 Coulombic efficiency 20
2.3.6 Cycling performance 20
2.3.7 Charge-transfer resistance (Rct) 21
2.3.8 Electrochemical impedance spectroscopy (EIS) 21
2.3.9 Cyclic voltammetry (CV) 24
CHAPTER 3: LITHIUM-ION BATTERY 25
3.1 Classification of battery 25
3.1.1 Primary (single discharge) Batteries 25
3.1.2 Secondary (rechargeable) batteries 25
3.2 Lithium-ion batteries 27
3.2.1 Basic Concept and Principle 27
3.2.2 Electrochemistry of Li-ion batteries 29
3.2.3 Anode and cathode materials 31
3.2.4 Electrolytes 37
3.2.5 Separators 39
CHAPTER 4: MATERIALS AND METHODS 40
4.1 Materials 40
4.2 Methods 41
4.2.1 Preparation and characterization of active material 41
4.3 Structure and microstructure analysis 42
4.3.1 X-ray diffraction (XRD) 42
4.3.2 Fourier Transform Infrared Spectroscopy (FTIR) 45
4.3.3 Transmission Electron Microscope (TEM) 46
4.3.4 X-ray photoelectron spectroscopic (XPS) 47
4.4 Optical measurements 48
4.4.1 UV-Visible spectroscopy and band gap determination 48
4.5 Dielectric measurements 49
4.6 Electrode Preparation and Cell Assembly 50
4.6.1 Electrode Fabrication 50
4.6.2 Coin Cell Assembly 53
4.7 Electrochemical Measurements 55
4.7.1 Cyclic Voltammetry (CV) 55
4.7.2 Electrochemical Impedance Spectroscopy (EIS). 56
4.7.3 Galvanostatic characterization 56
CHAPTER 5: RESULTS AND DISCUSSION 57
5.1 Structure and microstructure analysis 57
5.1.1 X-ray diffraction (XRD) 57
5.1.2 Transmission electron microscope (TEM) 63
5.1.3 XPS characterization and analysis 67
5.2 Optical properties 71
5.3 Dielectric properties 78
5.4 Electrochemical properties 89
5.4.1 Galvanostatic Cycling of the Electrochemical Cells 89
5.4.2 Cyclic Voltammetry (CV) of the Electrochemical Cells 93
5.4.3 Electrochemical Impedance Spectra (EIS) 94
Conclusion 95
Summary 97
References 98
List of Figures
Figure 2 1: Polarizability as a function of frequency. (Coelho, 2012), 14
Figure 2 2: Contrast between normal ferroelectrics and relaxor ferroelectrics (Samara, 2003). 16
Figure 2 3: Typical EIS curve of lithium-ion battery system. 20
Figure 2 4: Randles Circuit and Nyquist Plot 21
Figure 2 5: The consequential cyclic voltammogram (current voltage curve). 23
Figure 3 1: Schematic of a LIB during discharge 29
Figure 4 1: Fabrication process of material by sol-gel method 40
Figure 4 2: gel formation and Fabrication process of materials 41
Figure 4 3: Diffraction of X-ray waves by crystallographic planes. 42
Figure 4 4: The X-ray diffraction beamline MCX at Elettra (Plaisier et al., 2017) 43
Figure 4 5: PANalytical diffractometer 43
Figure 4 6: Bruker Tensor 27 FTIR Spectrometer 44
Figure 4 7: Schematic diagram of TEM microscope. 45
Figure 4 8: X-ray photoelectron spectroscopic (XPS) model KALPHA surface analysis 46
Figure 4 9: UV–Vis-2600 spectrophotometer, Shimadzu 47
Figure 4 10: (a)the sample pressed into pellets, (b)the pellet before and after being coated with silver paste. 48
Figure 4 11: TOB-XQM-0.2 planetary ball mill machine 50
Figure 4 12: doctor blading technique for coating slurry onto a copper foil 51
Figure 4 13: steps of cutting sheets into electrodes. 51
Figure 4 14: The Vigor glove box (Sci-Lab SG 1200/1000) 53
Figure 4 15: Coin-Cell assembly 53
Figure 4 16: battery tester (Bio-Logic MPG-205, France) 54
Figure 4 17: Randles equivalent circuit 55
Figure 5 1: X-ray diffraction patterns for ZnMn2−xVxO4 (0 ≤x≤ 0.4) 56
Figure 5 2: X-ray diffraction patterns for ZnMn2O4, graphene, MWNCT and ZnMn2O4/MWCNT/G 57
Figure 5 3: Rietveld refinement pattern fitting for ZnMn2O4 (synchrotron) 58
Figure 5 4: Rietveld refinement pattern fitting for ZnMn2-xVxO4 (a) x=0.1 and (b) x=0.4 59
Figure 5 5: a–c TEM images with different magnifications with the crystallographic planes and d the corresponding SAED pattern for ZnMn2O4 nano sample 62
Figure 5 6: selected area electron diffraction (SAED) patterns. 63
Figure 5 7: FTIR spectra for ZnMn2−xVxO4 (0 ≤x≤0.4) samples 65
Figure 5 8:(a) XPS survey spectra for ZnMn2−xVxO4 (0≤x≤ 0.4) samples, XPS fitting for (b) Zn 2p peaks, (c) Mn 2p and 3s peaks and (d) V 2p peaks. 67
Figure 5 9: (a) UV diffused reflectance for ZnMn2−xVxO4 (0≤x≤0.4) samples, (b) relation between (A/λ)2 vs 1/λ to calculate energy gap for ZnMn2O4 sample, and (c) energy gap composition dependence for ZnMn2−xVxO4 (0≤x ≤ 0.4) samples. 71
Figure 5 10: The wavelength dependence of (a) extinction coefficient (k), and (b) The wavelength dependence of refractive index (n) for ZnMn2−xVxO4 (0≤ x ≤0.4) nano-samples. 73
Figure 5 11: (a) the wavelength dependence of real part (εr), (b) imaginary part (εi) of dielectric constant, and (c) dielectric loss for ZnMn2−xVxO4(0 ≤ x≤ 0.4) nano-sized samples. 75
Figure 5 12: Energy dependence of (a) optical conductivity, and (b) electrical conductivity for ZnMn2−xVxO4 (0≤x≤0.4) nano-sized samples. 76
Figure 5 13: Frequency dependence of real dielectric constant for ZnMn2-xVxO4 (0≤x≤0.4) nano-sized samples at different temperatures. 80
Figure 5 14: (a) Frequency dependence of real dielectric constant part and (b) the variation of real dielectric constant part with amount of V doping at different frequencies for ZnMn2−xVxO4 (0≤x ≤0.4) nano-sized samples at 40 oC. 81
Figure 5 15: Frequency dependence of imaginary dielectric constant for ZnMn2−xVxO4 (0≤x≤0.4) nano-sized samples at different temperatures 82
Figure 5 16: Temperature dependence of real dielectric constant part for ZnMn2−xVxO4 (0≤x≤0.4) nano-sized samples at different frequencies. 83
Figure 5 17: Frequency dependence of a.c. conductivity for ZnMn2−xVxO4 (0 ≤ x≤ 0.4) nano-sized samples at different temperatures 84
Figure 5 18: (a) Frequency dependence of a.c. conductivity and (b) the variation of a.c. conductivity with amount of V doping at low frequency for ZnMn2−xVxO4 (0 ≤ x≤ 0.4) nano-sized samples at 40 oC. 85
Figure 5 19:Temperature dependence of universal exponent (s) for ZnMn2−xVxO4 (0≤x≤0.4) nano-sized samples 87
Figure 5 20: Initial discharge capacity of ZnMn2O4, ZnMn2O4 mixed with (MWCNT/G, MWCNT, G), and ZnMn1.99V0.01 anode materials at 100 mA g−1 88
Figure 5 21: Initial charge–discharge cycles of ZnMn2O4 and ZnMn2O4/MWCNT/G anode materials at 100 mA g−1 89
Figure 5 22: cycle life tests for the assembled ZnMn2O4 and ZnMn2O4/MWCNT/G batteries at current density 100 mA g−1 90
Figure 5 23: rate capability performance for the assembled ZnMn2O4/MWCNT/G batteries with different rates of current density. 91
Figure 5 24: CV curves for the first five cycles of pure ZnMn2O4 anode material versus Li metal at scan rate 0.1 mV s−1 92
Figure 5 25: Nyquist plots for the assembled ZnMn2O4 and ZnMn2O4/MWCNT/G batteries cycled at current density 100mA g−1 after the 10th charge–discharge cycle. 93
List of Tables
Table 3 1: The most common types of secondary batteries 25
Table 3 2: Most common anode materials used for lithium-ion batteries. 35
Table 4 1: materials and chemicals used. 39
Table 4 2: percentage of the cell components at different values of vanadium content (x). 50
Table 5 1: Lattice parameters (Å), strain (ST), crystallite size (nm), oxygen coordinates (0 y z), and bond length (Å) for ZnMn2−xVxO4 (0≤ x ≤0.4) nano-sized sample 60
Table 5 2: Cation distribution for ZnMn2−xVxO4 (0≤ x ≤0.4) 60
Table 5 3 :d spacing and the miller indices of the tetragonal structure 63
Table 5 4: XPS analysis for ZnMn2−xVxO4 (0 ≤x ≤0.4) nano-sized samples 68
List of Abbreviations
Abbreviation Full name
LIB’s Lithium-ion batteries
EV/HEV Electrical and hybrid electrical vehicles
G Graphene
CNT Carbon nanotube
SWCNT single Walled Carbon nanotube
MWCNT Multi Walled Carbon nanotube
CB Carbon black
PVDF Polyvinylidene difluoride
NMP 1-methyl-2-pyrrolidinone
XRD X-Ray Diffraction
XPS X-ray photoelectron spectroscopic
TEM Transmission Electron Microscope
FTIR Fourier Transform Infrared spectroscopy
UV Ultraviolet–Visible spectroscopy
CV Cyclic voltammetry
EIS Electrochemical impedance spectroscopy
SEI solid–electrolyte interface
AC Alternating current conductivity
OCP Open circuit potential
List of Symbols
Symbol Name Unit
∆G Gibbs free energy W
E Electrode potential V
F Farady constant = 96485 coulomb
𝑄𝑇𝑆𝐶 theoretical specific capacity F
M molecular weight of the active materials g mol-1
Qc specific charge capacity mAh g-1
Qd specific discharge capacity mAh g-1
Rct Charge-transfer resistance Ω
ipa Anodic peak current mA
Epa Anodic peak potential V
2θ Peak position of XRD °
∆Q Charged or discharged capacity C
C-rate Charged or discharged rate mA
Rs electrolyte resistance Ω
Ea Apparent activation energies kJ mol-1
σw Warburg impedance ohm
EO Oxidation peak potential V
ER Reduction peak potential V
f Frequency in the EIS test Hz
I Current density, A cm-2
IR Current density of reduction peak mA g-1
N Avogadro’s number = 6.022 × 1023 mol-1
ABSTRACT
Lithium-ion batteries (LIBs) are one of the most competitive energy storage systems for future renewable energy resources and electric automobiles. Lithium-ion batteries are widely used in various portable electronic devices such as mobile phones, tablets, camcorders, laptops, etc., owing to their compactness, light weight, longer cycle life, design flexibility, and environment friendliness.
The first task in this thesis is LIBs negative electrode formulation by preparing anodic materials that can easily intercalate and transfer Li-ions at appropriate high potentials and investigate their electrochemical properties. To accomplish this, Nano-ZnMn2O4, nano-ZnMn2-xVxO4 (0.0 ≤ x ≤ 0.4) system was prepared by a simple sol-gel procedure and ZnMn2O4/Multi Walled Carbon Nano Tube (MWCNT)/graphene (G) composites were prepared by sol-gel and ball-milling methods. The functional properties of the prepared samples were studied by applying various techniques. X-ray diffraction (XRD) and Rietveld analysis indicated a single-phase ZnMn2O4 with a partially inverse spinel nanostructure (average size ≈ 7 nm), also confirmed by TEM graphs, which revealed the morphology and particle nano-size distribution in samples. The samples were further characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy (XPS). The Gaussian fitting of Zn 2p and Mn 2p narrow XPS spectrum confirmed the cation distribution obtained from XRD Rietveld analysis. Also, the different optical parameters were explored for all samples using UV–Vis diffused reflectance technique. The optical bandgap is increased by increasing the V content (x) in the nano-ZnMn2-xVxO4 matrix. The dielectric characteristics and ac conductivity varied depending on the amount of V doping and purity of the samples. The mechanism of conductivity in the different samples was investigated in detail.
For electrochemical Measurements, the galvanostatic cycling of ZnMn2O4 electrode exhibited higher initial discharge capacity (" ~ " 1978 mAh g−1) when cycled at 100 mA g−1 versus Li/Li+. Meanwhile, the cyclic voltammetry tests evidenced the enhanced Li-ion diffusion during the oxidation and reduction processes. The assembled ZnMn2O4/MWCNT/G cell delivered about 190 mA h g−1 of specific discharge capacity over 100 cycles with 65% capacity retention