Studies on metal oxides as anodes for lithium ion batteries

STUDIES ON METAL OXIDES AS ANODES FOR LITHIUM ION BATTERIES BY NIDHI SHARMA (M. Sc., University of Roorkee) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF PHYSICS NATIONAL UNIVERSITY OF SINGAPORE 2005 Acknowledgements I would like to express my deep and sincere gratitude to my supervisor, Assoc. Prof. B. V. R. Chowdari of the Physics Department. His wide knowledge, logical way of thinking, understanding nature, encouragement and guidance have provided a good basis for the Thesis. I owe my sincere thanks to Prof. G. V. Subba Rao for his advice during my entire research endeavor. His observations and comments helped me to establish the overall direction of the research and to move ahead. I am thankful to Dr. K. M. Shaju for helping me with the experimental techniques involved in the synthesis and characterization of anode materials. I take the opportunity to extend my warmest thanks to Prof. T. J. White and Dr. J. Plevert from School of Materials Engineering, Nanyang Technological University, Singapore, for collaborating with us in HRTEM and XRD-Rietveld refinement studies. The financial support by way of research scholarship and facilities from National University of Singapore is gratefully acknowledged. My sincere thanks to the entire academic and administrative staff of the Department of Physics. Thanks are due to Assoc. Prof. Wee Thye Shen Andrew for allowing me use of the SEM and XPS facilities in the Surface Science Laboratory, Physics Department. I am also thankful to Mr. Wong How Kwong, Ms. Liu Yanjiao and Mr. Ho Kok Wen from Surface Science group for helping me in collecting XPS data and SEM photographs. I thank Mr. Tan Choon Wah, Mr. Hwang Hock Lin and other staff from Physics workshop for their support. The help rendered by our Lab officer Mr. Abdual Karim is worth acknowledging. i I am grateful to Mdm. Leng Lee Eng and Ms.Yap Souk Peng Serene of the Department of Chemistry for helping me with the Thermal analysis and XRD on powder samples. The research work done on lithium-ion battery (LIB), and anode materials for LIB available in the open literature has been duly acknowledged by referencing it appropriately in respective Chapters of the Thesis. I would like to thank my colleagues, Dr. M. V. Reddy and Mr. Yogesh Sharma for their help and interaction. I also acknowledge my friends, Mr. Lim Zee Han, Hor Wei Hann, Jeremey Chong, Anders Dawento, Cheong Fook Chiong, Reshmi Rajendran, Dr. S. Madhavi, Dr. Pratap Singh, Dr. M. Deepa, Vineet Srivastava, Nidhi Srivastava and Poonam Goel for their encouragement and help. I am indebted to my father (Dr. I. C. Sharma) for his consistent encouragement, support, motivation and whose research career has always been an inspiration for me to follow his foot-steps. A word of acknowledgement for my mother is too small. I have great regard for the support rendered by my husband Mr. Pankaj Sharma, by way of sharing family responsibilities, during my entire research period. Without his encouragement and understanding, it would have been impossible for me to finish this work. I owe my loving thanks to my sweet child (Sushmit Sharma) for allowing me to spend time on the thesis. I also wish to acknowledge my sisters (Mrs. Babita Sharma and Ms. Anamika Sharma) and my in-laws (Mrs. and Mr. Satendra Kumar). Above all, I would like to thank almighty, who directed me to take up this assignment. ii Table of Contents Acknowledgements i Table of contents iii List of Figures x List of Tables xiiiv Summary xx List of publications xxiv Chapter Introduction Abstract 1.1 Definition of Battery 1.1.1 Primary Batteries 1.1.2 Secondary Batteries 1.2 Development of Li-ion Batteries 1.3 Principle of Operation 1.4 World Market and Future Trends in LIB 1.5 Commercial LIB for Mobile Phones 1.6 LIB Technology Challenges 1.7 Need of R&D on LIB and Criterion for Selection of Electrode 10 Materials 1.8 Research Trends in the Field of Cathodes 12 1.8.1 4V-Cathodes 12 1.8.2 3.5 V-Cathode 15 1.8.3 5V-Cathodes 16 1.8.4 Theoretical approaches for identifying and rationalising 16 the Li-metal- oxides as cathodes for LIB iii 1.9 Research Trends on Anodes for LIB 1.9.1 Carbon 17 1.9.1.1 Types of carbon 1.9.1.1.1 1.9.2 1.9.3 Graphite 18 18 1.9.1.1.2 Non-graphitic carbons 19 1.9.1.1.3 Reaction mechanism 19 Alloy Anodes 21 1.9.2.1 Tin-based oxides 25 1.9.2.1.1 Amorphous tin composite oxides 25 1.9.2.1.2 Binary tin oxides 26 1.9.2.1.3 Ternary tin oxides 30 1.9.2.1.4 Tin oxide composites 32 Oxide Anodes based on Displacive Redox Reaction 1.9.3.1 Binary transition metal oxides 1.9.3.2 Ternary and complex transition metal oxides 1.9.4 17 Oxide Anodes based on Reversible Li-metal-oxide Bronze 33 33 37 38 Formation/Decomposition 1.9.4.1 Ternary oxides of vanadium 38 1.9.4.2 Ternary oxides of molybdenum 39 1.9.5 Oxide Anodes based on Li- intercalation/de- intercalation 40 1.9.6 Metal Nitrides, Sulfides, Phosphides and Fluorides 41 1.9.6.1 42 Metal fluorides 1.9.6.2 Metal nitrides 42 1.9.6.2.1 Binary nitrides 42 1.9.6.2.2 Ternary nitrides 43 iv 1.10 1.9.6.3 Metal phosphides 44 1.9.6.4 Metal sulfides 45 Electrolytes for LIB 46 1.10.1 47 Glassy and Ceramic Electrolytes for LIB 1.10.1.1 Oxide and sulfide glasses as solid electrolytes 47 1.10.1.2 Crystalline ceramic electrolytes 48 1.10.1.2.1 48 Perovskite electrolytes 1.10.1.2.2 NASICON type electrolytes 1.10.2 49 Polymer Electrolytes for LIB 49 1.10.2.1 Solid polymer electrolyte (SPE) 50 1.10.2.2 Gelled polymer electrolyte 51 1.11 LIB with non-Graphite Anodes 52 1.12 53 Motivation for the Present Study References 55 Chapter Experimental Techniques 2.1 Abstract 68 2.2 Introduction 68 2.3 Synthesis of Metal Oxide Powders 68 2.4 X-ray Diffraction 70 2.5 X-ray Photoelectron Spectroscopy 72 2.6 Scanning Electron Microscopy 73 2.7 Transmission Electron Microscopy (TEM) 74 2.8 Thermogravimetric Analysis 75 2.9 BET Surface Area 76 v 2.10 Fabrication of Coin Cell 77 2.10.1 Electrode Fabrication 77 2.10.2 Coin Cell Assembly 77 2.11 Electrochemical Studies 79 2.11.1 Galvanostatic Cycling 80 2.11.2 Cyclic Voltammetry 81 2.11.3 Electrochemical Impedance Spectroscopy (EIS) 83 2.11.3.1 Determination of diffusion coefficient of ions 86 from EIS 2.12 Other Electro-analytical Techniques References 86 89 Chapter Li-recyclability of ternary tin oxides with perovskite and Sr2PbO4 structure 3.1 Abstract 91 3.2 Introduction 92 3.3 Experimental 94 3.4. Results and Discussion 96 3. 3.4.1 Characterization by XRD, SEM and XPS 96 3.4.2 Galvanostatic Cycling 106 3.4.3 Cyclic Voltammetry 117 Conclusions 122 References 124 vi Chapter Tin oxides with hollandite structure as anodes for Li-ion batteries 4.1 Abstract 127 4.2 Introduction 128 4.3 Experimental 131 4.4 Results and Discussion 133 4.4.1 Structure and Morphology 133 4.4.2 XPS of Hollandites 137 4.4.3 Galvanostatic Cycling of Sn-hollandites 139 4.4.4 Cyclic Voltammetry of Sn-hollandites 146 4.4.5 Electrochemical Impedance Spectroscopy (EIS) of 148 K2(Li2/3Sn22/3)O16 4.5 4.4.5.1 First-discharge and -charge cycle 148 4.4.5.2 Impedance spectra during the 15th discharge –charge cycle 154 Conclusions 156 References 158 Chapter Mixed transition metal oxides as anodes for Li-ion batteries 5.1 Abstract 162 5.2 Introduction 163 5.3 Experimental 165 5.4 Results and Discussion 166 5.4.1 XRD 166 5.4.2 SEM 170 5.4.3 Electrochemical Studies of Compounds with 171 CaFe2O4 Structure vii 5.4.3.1 Galvanostatic cycling 171 5.4.3.2 Cyclic voltammetry of compounds with 182 CaFe2O4 structure Electrochemical Studies on Ca2Fe2O5 and 5.4.4 186 Ca2Co2O5 5.4.4.1 Galvanostatic cycling 186 5.4.4.2 Impedance spectroscopy of Ca2Co2O5 193 5.4.4.3 Cyclic voltammetry of Ca2Fe2O5 199 and Ca2Co2O5 5.5 Conclusions 201 References 204 Chapter Carbon coated nanophase CaMoO4 and CaWO4 as anode materials for Li-ion batteries 6.1 Abstract 207 6.2 Introduction 208 6.3 Experimental 209 6.4 Results and Discussion 211 6.4.1 Structural Characterization 211 6.4.2 6.4.1.1 TGA of CaMoO4 and CaWO4 211 6.4.1.2 XRD of CaMoO4 and CaWO4 214 6.4.1.3 SEM of CaMoO4 and CaWO4 216 6.4.1.4 TEM of CaMoO4 218 Electrochemical Cycling Studies on CaMoO4 219 6.4.2.1 Galvanostatic cycling 219 6.4.2.2 Cyclic voltammetry 228 viii 6.4.3 6.5 6.4.2.3 Charge-discharge reaction mechanism 230 Electrochemical Studies on CaWO4 233 6.4.3.1 Galvanostatic cycling 233 6.4.3.2 Ex-situ XRD and reaction mechanism 239 6.4.3.3 Cyclic voltammetry 242 6.4.3.4 Electrochemical impedance spectroscopy 243 Summary and Conclusions 250 References 252 Conclusions and suggestions for further study 256 Credits to Publishers 261 ix frequency range (0.35 MHz-2.2 Hz) followed by a straight line in the low frequency side. Changes occur in the spectra at various voltages, 1.0- to-0.005 V as the result of a number of processes, i.e., crystal structure destruction, electrochemical reaction represented by Eqns. (6.4) and (6.5), formation of the solid electrolyte interface (SEI) involving reaction with the electrolyte, the charge transfer process and any changes in the bulk conductivity of the active material, ‘LixWOy’. Since only one well-defined semicircle was seen in all the spectra, they were fitted with the circuit Re, R 65M) at 100 cycles in the voltage range 0.005-1.0 V. The theoretically achievable capacity value is 570 mAh/g (4.4 moles of Li). Therefore, scope exists for improvement in achievable capacity possibly by adopting new and novel methods of synthesis and carbon coating. (ii) Studies on C-coated CaMoO4 showed that optimum carbon-coating is between and 10%. The precise value of optimum carbon content is yet to be determined. (iii) CaSnO3, Ca2Co2O5 and CaMoO4 have been proposed as the prospective anode materials for LIB. Their true applicability is yet to be established by using them in practice in a LIB in conjunction with LiCoO2 cathodes. 259 (iv) Li-cyclability up to 2.9 moles/Sn in CaSnO3 and capacity fading on cycling in K2(Li2/3Sn22/3)O16 necessitates research work on crystalline mixed-tin-oxides to arrive at an optimum crystal structure and matrix element for use in LIB. (v) Our comparative study on the choice of various matrix elements proved that ‘Ca’ is the best matrix element. An explanation for this behaviour is yet to be found and further studies are needed to understand the actual role of matrix element. Also, the role of the starting crystal structure of the mixed oxide towards the Licyclability needs to be understood, although the structure gets destroyed in the first-discharge cycle. 260 Credits to Publishers This is a grateful acknowledgement to the publishers who have permitted me to reprint figures from their book. No. Figure/Page No.s Credit 1. Fig. 1.1/p2 Reprinted from “Handbook of Batteries”, 3rd edition, eds., D. Linden and T. Reddy, Chapter 35/ Lithium Ion Batteries, Figure 1.4, p1.15, Copyright (2002) with kind permission from The McGraw-Hill Companies, Inc. 2. Fig. 1.2/p5 1.9/p18 Reprinted from “Materials Science & Engineering R33(2001)109”, M. Wakihara, Figure 2/ p112 and Figure 4/p114 Copyright (2001) with kind permission from Elsevier. 3. Fig. 1.31.6(p5,8,9,9) Reprinted from “Advances in lithium-ion batteries”, eds., W. A. van Schalkwijk, B. Scrosati, Fig. 11/p244, Fig. 7/p241, Fig. 9/243, Fig. 10/p244, Copyright (2004) with kind permission from Springer Science and Business Media. 4. Fig. 1.10/p20 Reprinted from “Lithium Batteries-Science and Technology”, eds., G-A Nazri and G. Pistoia, Figure 5.5/ p158, Copyright (2004) with kind permission from Springer Science and Business Media. 5. Fig. 1.11,1.17/ p27,52 Reprinted from “Electrochem. Solid State Letters 2(1999)365”, S. Panero, G. Savo, B. Scrosati, Figure and 4/p 366, Copyright (1999) with kind permission from The Electrochem. Soc. Inc., USA. 6. Fig. 1.12/p27 Reprinted from “Journal of the Electrochemical Society 144 (1997) 2045”, I. A.Courtney, J.R.Dahn, Fig. 13/p 2051, Copyright (1997) with kind permission from The Electrochem. Soc. Inc., USA. 7. Fig. 1.13/p29 Reprinted from “Journal of the Electrochemical Society 146(1999)59”, I. A.Courtney, W.R.McKinnon, J.R.Dahn, Fig. 1/p 59, Copyright (1999) with kind permission from The Electrochem. Soc. Inc.,USA. 8. Fig. 1.14/p34 Reprinted from “Journal of Power Sources 9798(2001)235”, P.Poizot, S. Laruelle, J. M. Tarascon, Fig. 1/p236 Copyright (2001) with kind permission from Elsevier. 9. Fig. 1.15/p36 Reprinted from “Journal of the Electrochemical Society 261 149 (2002) A627”, S. Laruelle, S. Grugeon, P. Poizot, M. Dolle, L. Dupont, J.- M. Tarascon, Fig. 9/p A632, Copyright (2002) with kind permission from The Electrochem. Soc. Inc., USA. 10. Fig. 1.16/p41 Reprinted from “Journal of Power Sources 83 (1999) 156”, G.X.Wang, D.H.Bradhurst, S.X.Dou, H. K. Liu, Fig. 3,4/p159 Copyright (1999) with kind permission from Elsevier. 11. Table 1.1/p7 Reprinted from “Lithium Batteries-Science and Technology”, eds., G-A Nazri and G. Pistoia, Tables 23.1 and 23.2/ p703, Copyright (2004) with kind permission from Springer Science and Business Media. 12. Table1.2/p8 Reprinted from “Advances in Lithium-Ion Batteries”, eds., W. A. van Schalkwijk, B. Scrosati, Table 1/p248, Copyright (2004) with kind permission from Springer Science and Business Media. 13. Table1.6/p47 Reprinted from “Materials Science & Engineering R33(2001)109”, M. Wakihara, Table 3/ p118, Copyright (2001) with kind permission from Elsevier. 14. Table 1.7/p51 Reprinted from “Journal of Power Sources 51(1994)79”, S. Megahed, B. Scrosati, Table 2/p93, Copyright (194) with kind permission from Elsevier. 15. Fig. 2.4/p82 Modified from “Journal of Power Sources 147 (2005) 241”, K. S. Tan, M. V. Reddy, G. V. Subba Rao, B. V. R. Chowdari, Fig. 3/p45, Copyright (2005) with kind permission from Elsevier. 262 [...]... p87-95 3 “Iron-tin oxides with CaFe2O4 structure as anodes for Li -ion batteries , N Sharma, K M Shaju, G V Subba Rao, B V R Chowdari, J Power Sources 124 (2003) 204-212 4 “Mixed oxides Ca2Fe2O5 and Ca2Co2O5 as anode materials for Li -ion batteries , N Sharma, K M Shaju, G V Subba Rao, B V R Chowdari, Electrochim Acta, 49 (2004)1035-1043 5 “Recent studies on Metal oxides as anodes for Li -ion batteries ,... such as Li -metal alloy formationdecomposition or displacive redox reaction involving nano-size metal or Li -metal oxide ‘bronze’ Chapter 1 describes the LIB, principle of operation, development of LIB, world market and future trends This is followed by the literature survey on the three important battery components: cathodes, anodes, and electrolytes and realization of LIB using non-graphitic anodes. .. lithium ion batteries (LIB) is presented The principle of operation of LIB, world market, present and future trends of LIB are described This is followed by a literature survey on the battery components- cathodes, anodes and electrolytes for LIB The concluding section describes the motivation for the present study on the anodes for LIB 1.1 Definition of Battery A battery is a device that transforms chemical... moles of Li per formula unit for CaWO4 (current rate, 60 mA/g) 237 xix Summary Lithium ion batteries (LIB) are acclaimed as the advanced power sources among all rechargeable batteries Their energy density and cycle-life are a function of the choice of the electrode and electrolyte materials This Thesis presents studies on mixed metal oxides as prospective anodes for LIB based on the principle of Lirecyclability... The operation of LIB is based on the principle of insertion/de-insertion of Liions in electrode materials via an ionically conducting medium called electrolyte Hence, it is a pre-requisite for an electrode material that it should be capable of reversible Li insertion Indeed, a large number of compounds involving different chemistries were proposed as prospective LIB electrodes-cathodes and anodes In... predictability of LIB performance are on top priority 1.7 Need of R&D on LIB and Criterion for Selection of Electrode Materials Although LIB are commercially available as small battery-pack for portable electronic devices, they are expensive and serious R&D is needed to overcome the aforementioned issues listed in section 1.6 Attempts are to be made to replace the 10 toxic and costly metal (cobalt) for cathodes... SrSnO3, (c ) BaSnO3 and (d) Ca2SnO4 Base line and curve fitting of the raw data are shown The 3d5/2 and 3d3/2 regions are indicated 101 Fig.3.4 XPS spectra in the O-1s region of (a) CaSnO3, (b) SrSnO3, (c ) BaSnO3, and (d) Ca2SnO4 Base line and curve fitting of the raw data are shown 102 xi Fig.3.5 XPS spectra in (a) Ca-2p region of CaSnO3, (b) Sr 3d region of SrSnO3, (c) Ba 3d region of BaSnO3 and (d)... Li In conjunction with another non-metallic Li-accepting compound as cathode, the electrochemical cycling process would involve the transfer of Li-ions between the electrodes This approach has led to development and commercialization 3 of Li -ion batteries (LIB) The development of LIB and the electrode materials have been described in various books and papers [3-6, 9-14] 1.3 Principle of Operation The... density and charge retention of these batteries are poorer than those of primary batteries Well-known examples are: Lead acid, Nickel cadmium, Nickel -metal hydride and Li -ion batteries Their theoretical and actual specific energy are shown in Fig 1.1 Presently, the Li -ion and the nickel metal hydride batteries have been acclaimed as advanced power sources for portable applications Fig 1.1 Energy storage... year 1998, the flat pack configuration has been introduced Due to packaging flexibility the flat pack was considered superior to the cylindrical configuration LIB are also being investigated for use in areas demanding large power-packs, such as to power electric vehicles (EV), hybrid electric vehicles (HEV) [4,15-18], satellites and other space applications [4] Such applications need high voltage (36 . Conclusions 156 References 158 Chapter 5 Mixed transition metal oxides as anodes for Li -ion batteries 5.1 Abstract 162 5.2 Introduction 163 5.3 Experimental 165 5.4 Results and Discussion. transition metal oxides 37 1.9.4 Oxide Anodes based on Reversible Li -metal- oxide Bronze 38 Formation/Decomposition 1.9.4.1 Ternary oxides of vanadium 38 1.9.4.2 Ternary oxides of molybdenum. tin oxides 30 1.9.2.1.4 Tin oxide composites 32 1.9.3 Oxide Anodes based on Displacive Redox Reaction 33 1.9.3.1 Binary transition metal oxides 33 1.9.3.2 Ternary and complex transition metal