Luận án nghiên cứu quá trình tổng hợp vật liệu nano silic để chế tạo anode định

MINISTRY OF EDUCATION AND TRAINING MINISTRY OF NATIONAL DEFENCE ACADEMY OF MILITARY SCIENCE AND TECHNOLOGY NGUYEN VAN THANG STUDY ON THE SYNTHESIS PROCESS OF SILICON NANOMATERIALS TO FABRICATE ANODE ORIENT APPLICATION FOR Li-ION BATTERIES DOCTORAL THESIS OF CHEMISTRY Hanoi – 2019 MINISTRY OF EDUCATION AND TRAINING MINISTRY OF NATIONAL DEFENCE ACADEMY OF MILITARY SCIENCE AND TECHNOLOGY NGUYEN VAN THANG STUDY ON THE SYNTHESIS PROCESS OF SILICON NANOMATERIALS TO FABRICATE ANODE ORIENT APPLICATION FOR Li-ION BATTERIES Specialization: Theoretical chemistry and Physical chemistry Code: 9 44 01 19 DOCTORAL THESIS OF CHEMISTRY Scientific supervisors: Dr. Nguyen Tran Hung Assoc. Nguyen Manh Tuong Hanoi – 2019 i STATEMENT OF AUTHORSHIP I assure that the thesis is my own research work. The data and results presented in the dissertation are honest and have not been unpublished in other work.

The reference is fully cited. Hanoi, date: Ph.D student Nguyen Van Thang ii ACKNOWLEDGMENTS First of all, I would like to express their deep gratitude to my supervisors Dr. Nguyen Tran Hung and Assoc. Nguyen Manh Tuong for their direct instruction guidance and support throughout my thesis implementation process.

I am grateful for the help of the Training Department, Academy of Military Science and Technology throughout the complete process of the thesis. I sincerely express my deepest thanks to the head of the Institute of Materials - Chemistry, the head of the Nanomaterials Department, the colleagues and my friends for their encouragement.D student Nguyen Van Thang iii TABLE OF CONTENTS Page LIST OF FIGURES .vi LIST OF TABLES .x LIST OF SYMBOLS AND ABBREVIATIONS. Overview of LIB. The new generation of electrochemical sources.

Domestic and foreign research situation on LIB. Anode materials of LIB. Ion storage material. Anode from silicon material, silicon nanoparticles/graphene.

Methods of synthesis silicon nanoparticles and current progress of thermodynamics, the kinetics of synthesis of silicon nanoparticles from rice husk. Overview of silicon. Introduction about rice husk and current status of rice husk use in our country. The synthesis nano Si from rice husk.

Synthesis methods of graphene. Overview of graphene. Synthesis methods of graphene. Kinetics and thermodynamics.

Thermal analysis and reaction kinetics study by thermal analysis.39 CHAPTER 2: SUBJECTS AND METHODS OF RESEARCH. The synthesis method of nano Si from rice husk. Kinetic, thermodynamic characteristics of synthesis nano Si from rice husk. Synthesis of rGO from graphite.

Synthesis of nano Si@rGO material for LIB's anode. Fabrication of LIB to test electrochemical properties of anode materials. The fabrication process of LIB’s anode. LIB fabrication process.

Methods of studying the composition and material structure. Scanning electron microscope (SEM) method. Energy-dispersive X-ray spectroscopy (EDX) method. Transmission electron microscopy (TEM) method.

Fourier-transform infrared spectroscopy method (FT-IR). X-ray diffraction method (XRD). Isothermal method adsorbed gas nitrogen. Methods of surveying electrochemical properties of electrodes.

Galvanostatic charge-discharge (GC) .55 CHAPTER 3: RESULTS AND DISCUSSION. Synthesis silica nanoparticles from rice husk. Investigate the effects of acid treatment. Investigate the effects of calcination mode.

Thermodynamics, the kinetics of the process of synthesis silica nanoparticles from rice husk. Synthesis of silicon nanoparticles from silica nanoparticles. Investigation of factors affecting silicon nanoparticles synthesis process. Kinetics of the process of synthesis silicon nanoparticles from silica nanoparticles.

Synthesis nano rGO and nano Si@rGO. Synthesis nano rGO. Investigate the structure and composition of nano Si@rGO materials. Application of rGO, nano Si and nano Si@rGO materials for fabrication LIB’s anode.

Experimental fabrication anode material combination. The electrochemical characteristics of LIB. Conclusion of chapter 3. 107 LIST OF PUBLICATIONS RELATING TO THESIS.

109 LIST OF REFERENCES. 110 vi LIST OF FIGURES Pages Figure 1. Comparison of energy densities and specific energy of different rechargeable batteries. Some Li-ion batteries on the white background.

Schematic of the electrochemical process in LIB. Structures of common cathode materials:. The model illustrates the formation of host-guest compound. Schematic picture of the failure mechanism of silicon nanoparticles during cycling.

Schematic process for fabricating the silicon nanoparticles/graphene nanocomposite. Schematic of silicon synthesis silicon nanoparticles by chemical vapor deposition of silanes. Schematic of silicon synthesis by electrochemical etching method. Graphene is the basic structure of other carbon nanostructures.

The bonds of carbon atoms in the graphene. Image illustrating graphene oxide film. The thermal reducing reaction of hydroxyl groups. The thermal reducing reaction of carbonyl groups.

Process of synthesizing silica nanoparticles from rice husk. Process of synthesizing silicon nano from silica nano. Schematic diagram of the reduction facility for silicon nanoparticles synthesis process. rGO synthesis process from graphite.

The thermal reduction process of GO in the furnace. The synthesis process of nano Si@rGO. The fabrication process of LIB’s anode. LIB with the two-electrode structure and glove box.

Cyclic voltammetry waveform. LIB with the two-electrode structure to measure electrochemical characterizations. TG/DTA curve of rice husk at the heating rate of 3 oC/min. SiO2 content in rice husk ash dependence on acid treatment time.

SiO2 content in rice husk ash dependence on acid treatment temperature. SiO2 content in rice husk ash dependence on ratio rice husk/HCl acid. Influence of calcination temperature on SiO2 content in rice husk ash. Influence of calcination time on SiO2 content in rice husk ash.

SEM images of rice husk ash samples after calcination at the temperature of 650 oC at the heating rates of 3, 6, 9, 12, 15 oC/min, respective. SEM and EDX images of nano SiO2. Particle size distribution of nano SiO2. XRD pattern of nano SiO2.

SEM image of nano SiO2 sample in high-resolution.12: TEM image of nano SiO2. DSC curves of rice husk pyrolysis process with heating rates of 3, 6, 9, 12, 15 oC/min. Plots of lg and 1/Tp of RHs of the F-W-O model. Plots of ln(β/Tp2) and 1/Tp of RHs of the Kissinger model.

DTA curves of rice husk pyrolysis process with heating rates of 3, 6, 9, 12, 15 oC/min. Plots of lg and 1/Tp of RHs of the F-W-O model. Plots of ln(β/Tp2) and 1/Tp of RHs of the Kissinger model. Si content dependence on mol ratio Mg/SiO2.

Si content dependence on calcination temperature. SEM images of nano Si samples obtained by magnesiothermic reduction of nano SiO2 with heating rates of 5 °C/min and 15 °C/min. N2 adsorption-desorption isotherms and the pore size distribution of nano Si RH-5. DSC curves of the reaction between nano SiO2 and Mg with different ramp rates.

XRD pattern of nano Si RH-5. Particle size distribution of nano Si RH-5. TEM image of nano Si RH-5. DSC curves of nano SiO2 reduction process with Mg with heating rates of 5, 9, 12, 15 oC/min.

Plots of lg and 1/Tp in the reduction of SiO2 by Mg of the F-W-O model. Plots of ln(β/Tp2) and 1/Tp in the reduction of SiO2 by Mg of Kissinger model. GO gel after acid washing. GO gel after freeze-drying.

Graphite particle size distribution. GO particle size distribution. FT-IR spectra of graphite. FT-IR spectra of GO.

TG/DTA curve of GO at the heating rate of 10 oC/min. XRD pattern of graphite. XRD pattern of GO. SEM image of graphite.

SEM image of GO. TEM image of GO. Image of rGO sheets. FTIR spectra of rGO.

TG/DTA curve of GO at the heating rate of 10 oC/min. SEM images of rGO at different resolutions. XRD pattern of rGO. EDX pattern of rGO (M1.

EDX pattern of rGO (M2. EDX pattern of nano composite Si@rGO. XRD pattern of nano composite Si@rGO. SEM, TEM images of nano composite Si@rGO.54: Schematic for synthesis process of nano composite Si@rGO.

Compound slurry of nano composite Si@rGO/cacbon/PVDF + NMP. LIB’s anode with a 11 mm diameter. Material structure of anode/cacbon/PVDF.58: SEM image and EDX pattern of carbon superP. SEM image of the anode/cacbon/PVDF material.

Cyclic voltammetry curves of LIB with anode fabricated on rGO basis of the first two cycles at a scan rate of 0.1 mV/s in the voltage range of 0. Cycling performance of LIB with anode fabricated on rGO basis under the current rate 0.2 mA/g) in the voltage range of 0. The rate capability of LIB with anode fabricated on rGO basis at the current rates from 37. Cyclic voltammetry curves of LIB with anode fabricated on nano Si basis of the first two cycles at a scan rate of 0.1 mV/s in the voltage range of 0.

Galvanostatic discharge-charge profiles of LIB with anode fabricated on nano Si basis at the current rate of 0.05C in the voltage range of 0. Cycling performance of LIB with anode fabricated on nano Si basis under the current rate 0.1C in the voltage range of 0. Cyclic voltammetry curves of LIB with anode fabricated on nano Si@rGO basis of the first two cycles at a scan rate of 0.1 mV/s in the voltage range of 0. Galvanostatic discharge-charge profiles of LIB with anode fabricated on nano Si@rGO basis at the current rate of 0.05C in the voltage range of 0.

Cycling performance of LIB with anode fabricated on nano Si@rGO basis under the current rate 1.5C in the voltage range of 0. The rate capability of LIB with anode fabricated on Si@rGO basis at the different current rates in the voltage range of 0. 104 x LIST OF TABLES Pages Table 1. Characteristics of cathode materials.

Advantages and disadvantages of LIB. Characteristics of cathode materials. Properties of graphene. Typical analysis of rice husk.

Typical analysis of Mg powder. Samples of materials after grinding in the process of synthesis rGO. Properties of copper foil. Properties of lithium foil.

SiO2 content in rice husk ash dependence on. Basic kinematic parameters according to the FWO model and Kissinger model in rice husk pyrolysis process. Basic kinetic parameters according to the FWO model and Kissinger model in rice husk pyrolysis process. Thermodynamic parameters of the synthesis of silica nanoparticles from rice husk.

Si content dependence on molar ratio Mg/SiO2. Basic kinetic parameters according to the FWO model and Kissinger model in the reduction of SiO2 by Mg. The electrochemical characteristics of LIB with anode fabricated on rGO, nano Si and nano Si@rGO basis and previous publications. 104 xi LIST OF SYMBOLS AND ABBREVIATIONS Ah Ampere-hour Anode An electrode of the battery C Capacity Cathode An electrode of the battery CE Counter Electrode CMC Carboxymethyl cellulose CNF Carbon nanofiber CNT Carbon nanotube CV Cyclic voltammetry CVD Chemical Vapor Deposition DMC Dimethyl carbonate DoD Depth of discharge DSC Differential scanning calorimetry DTA Differential Thermal Analysis e Electron EC Ethylen cacbonate EDX/EDS Energy–dispersive X-ray spectroscopy EMC Ethyl methyl carbonate FE-SEM Field Emission Scanning Electron Microscopy FT-IR Fourier transform infrared spectroscopy FWO Flynn-Wall-Ozawa model GC Galvanostatic Cycling GO Graphene oxide LIB Li-ion battery Li-ion Lithium ion MA Methyl acetate xii mAh Milliampere-hour mAh/g Milliampere-hour/gram MCMB MesoCarbon MicroBeads NiCd Nickel cadmium NiMH Nickel metal hydride NMP N-methylpyrrolidinone PC Propylene cacbonate PDDA Poly (diallyl dimethyl ammonium) PTC Positive thermal coefficient PTFE Poly (tetrafluoroethylene) PVA Poly (vinyl alcohol) PVDF Poly (vinylidene fluoride) Wh/kg Watt-hour/kilogram Wh/l Watt-hour/litre R Resistance RE Reference Electrode rGO Reduced Graphene Oxide SEI Solid Electrolyte Interphase SEM Scanning Electron Microscopy TGA Thermal Gravicmetric Analysis SUP-P Super-P, Carbon black WE Working Electrode XRD X-ray Diffraction 1 INTRODUCTION 1.

The urgency of the thesis topic The phenomenon of global warming, energy shortage worldwide, the increasing of pollution in cities are serious challenges that promote the replacement of fossil fuels that cannot be renewed by green energy sources such as solar energy, wind energy and nuclear energy,.Compared to the traditional fossil fuels, most green energy sources often depend on the geographical location of each region, weather and season, so that the energy conversion devices cannot be operated continuously, the efficiency is not high. For nuclear energy, there are many potential risks of radiation damage to human health and the environment.