University of Rhode Island DigitalCommons@URI Open Access Dissertations 2012 IMPROVING ELECTROLYTES FOR LITHIUM-ION AND LITHIUM OXYGEN BATTERIES Dinesh Chalasani University of Rhode Island, [email protected] Follow this and additional works at: https://digitalcommons.uri.edu/oa_diss Recommended Citation Chalasani, Dinesh, "IMPROVING ELECTROLYTES FOR LITHIUM-ION AND LITHIUM OXYGEN BATTERIES" (2012). Open Access Dissertations. Paper 96. https://digitalcommons.uri.edu/oa_diss/96 This Dissertation is brought to you for free and open access by DigitalCommons@URI. It has been accepted for inclusion in Open Access Dissertations by an authorized administrator of DigitalCommons@URI. For more information, please contact [email protected]. IMPROVING ELECTROLYTES FOR LITHIUM-ION AND LITHIUM OXYGEN BATTERIES BY Dinesh Chalasani A DISSERTATION SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR DOCTOR OF PHILOSOPHY IN CHEMISTRY UNIVERSITY OF RHODE ISLAND 2012 DOCTOR OF PHILOSOPHY DISSERTATION OF Dinesh Chalasani APPROVED: Thesis Committee: Major Professor Brett L. Lucht William B. Euler David R. Heskett Nasser H. Zawia DEAN OF THE GRADUATE SCHOOL UNIVERSITY OF RHODE ISLAND 2012 ABSTRACT There is an ever increasing demand for fossil fuels. Lithium ion batteries (LIBs) can effectively reduce the production of greenhouse gases and lessen the need for fossil fuels. LIBs also have great potential in electric vehicle applications as an alternative to petroleum modes of transportation. Understanding the chemical reactions between the electrolyte and electrodes in LIBs is very crucial in developing batteries which can work over a wide temperature range and also give a wide potential window. The Solid Electrolyte Interface (SEI), formed by the reduction of solvent molecules on the surface of electrodes, is an important component of LIBs. The SEI is very essential to the performance of LIBs. One electron reduction pathway products of solvent molecules was investigated using lithium-naphthalenide. Methylene ethylene carbonate, a high temperature additive has been synthesized and its performance has been tested at 60 oC. Lithium-Oxygen batteries have an energy density ten times greater than that of LIBs. However, lithium-oxygen batteries have rechargability problems associated with them. The most common electrolyte used in this type of batteries is LiPF 6 in carbonate or ether based solvents. LiPF 6 inherently decreases electrolyte stability, since LiPF 6 can undergo thermal dissociation into PF 5 and LiF. PF 5 being a strong Lewis acid, can react with electron rich species. The thermal decomposition reactions of LiPF 6 based electrolytes are studied in detail with regard to LIBs. The comprehensive study has been conducted on the thermal degradation of several electrolyte systems in the presence of Li 2O2. ACKNOWLEDGMENTS I would like to thank Dr. Brett L. Lucht for all his guidance during my graduate studies at URI. I am grateful to Dr. Lucht for his patience and the scientific knowledge he shared with the group. I am also thankful to Dr. Euler for his advice during all the group meetings which helped a lot in understanding many concepts. I would like to thank my thesis committee Dr. David R. Heskett, Dr. Sze C.Yang and Dr. Godi Fischer for spending their valuable time in reading this thesis. I would like to thank chemistry department in helping me in preparing for this graduate program. I would like to thank all my friends Christina , Liu Zhou, Mengquing Xu, Swapnil Dalavi, Ron Donn, Sravanthi, Ajay, Varun and Brandon for their valuable suggestions and helping through all these years. I would like to thank my family, my parents, my sister and my grandmother who are very encouraging and supporting me all these years. I would like to thank my wife Kalyani, without her support this couldn’t be possible. iii PREFACE This dissertation is written in manuscript format. The first chapter is an introduction about lithium ion batteries and lithium oxygen batteries. The second chapter is a manuscript that will be submitted to ECS electrochemistry letters. The third chapter is a manuscript published in The Journal of Power Sources. The fourth chapter is a manuscript that is published in ECS electrochemistry letters. The fifth chapter is a manuscript that is published in the Journal of polymer science A. iv TABLE OF CONTENTS ABSTRACT ................................................................................................................... ii ACKNOWLEDGMENTS ............................................................................................ iii PREFACE ..................................................................................................................... iv TABLE OF CONTENTS ............................................................................................... v LIST OF TABLES ....................................................................................................... vii LIST OF FIGURES .................................................................................................... viii Chapter 1. Introduction .................................................................................................. 1 Design of Lithium ion battery................................................................................2 Interface in lithium ion batteries ...................................................... …………….3 Additives for lithium ion batteries.........................................................................5 Lithium/oxygen battery..........................................................................................5 References……………..........................................................................................7 Chapter 2. Reduction products of Solid Electrolyte interface………………………...13 Introduction……………………………………………………………………...13 Experimental…………………………………………………………………….14 Results and Discussion…………………………………………………………..16 Conclusions……………………………………………………………………...19 References……………………………………………………………………….20 Chapter 3 Methylene ethylene carbonate: Novel additive to improve the High temperature performance of lithium ion batteries…………………………………….28 Introduction………………………………………………………………….......28 v Experimental……………………………………………………………….........29 Results and Discussion………………………………………………………......31 Summary………………………………………………………………………..36 References………………………………………………………………….…....38 Chapter 4 Reactivity of electrolytes for Lithium-Oxygen Batteries with Li 2O2 ……..49 Introduction…………………………………………………………….…….….49 Experimental………………………………………………………………….…50 Results and Discussion………………………………………………………..…51 Conclusions……………………………………………………….………….......55 References……………………………………………………………………….57 Chapter 5 Two-Step Thermochromism in Poly(3-docosoxy-4- methylthiophene):Mechanistic Similarity to Poly(3-docosylthiophene)……………..67 Introduction……………………………………………………………………...67 Experimental.……………………………………………………………………68 Results and Discussion.……………………………………………………….…70 Conclusions.…………………………………………………………………..…73 References.………………………………………………………………………74 vi LIST OF TABLES TABLE I. Chapter 1 Table 1-1. Physical properties of various organic solvents used in lithium ion batteries………………………………………………………………………….11 II. Chapter 2 Table 2-1. 1H NMR, 13 CNMR and GC-MS of the precipitates and gases formed by reaction of Lithium-naphthalenide with various organic carbonates ……………… 21 III. Chapter 3 Table 3-1. Elemental composition of C, F, O and P on anodes………………...39 Table 3- 2. Elemental composition of C, F, O, P and Ni on cathodes……….....40 IV. Chapter 5 Table 5-1. Summary of measured properties…………………………………..77 vii LIST OF FIGURES PAGE Chapter 1. Figure 1-1. Schematic diagram of the lithium ion battery discharge process…9 Figure 1-2 Charge and discharge process in Li/O 2 battery…………………...10 Chapter 2 Figure 2-1. 1H NMR of the precipitate formed in the reaction between EC and Lithium naphthalenide………………………………………………………..22 Figure 2-2. 13 C NMR of the precipitate formed in the reaction between EC and Lithium naphthalenide………………………………………………………..22 Figure 2-3. 1H NMR of the precipitate formed in the reaction between PC and Lithium naphthalenid ………………………………………………………...23 Figure 2-4. 13 C NMR of the precipitate formed in the reaction between PC and Lithium naphthalenide………………………………………………………..23 Figure 2-5. 1H NMR of the precipitate formed in the reaction between DEC and Lithium naphthalenide in D 6 acetone…………………………………….24 Figure 2-6 13 C NMR of the precipitate formed in the reaction between DEC and Lithium in D 6 Acetone…………………………………………………...24 viii Figure 2-7 1H NMR of the precipitate formed in the reaction between DMC and Lithium naphthalenide……………………………………………………25 Figure 2-8. 13 C NMR of the precipitate formed in the reaction between DMC and Lithium naphthalenide…………………………………………………...25 Figure 2-9 FTIR spectra of precipitates formed in reaction of Lithium- naphthalenide with: (a) Propylene carbonate (b) Ethylene carbonate (c) Diethyl carbonate (d) Dimethyl carbonate…………………………………………….26 Chapter 3 Figure 3-1. Discharge capacity vs cycle number for Li[Ni 1/3 Co 1/3 Mn 1/3 ]O 2- based cells containing 1 M LiPF 6 in 3:7 EC/EMC with and without added MEC. The cells were cycled at 1C rate between 3.0 and 4.2 V at 60 °C……..41 Figure 3-2. XPS spectra of anodes (a)Fresh anode (b) 1MLiPF6 in EC:EMC:DEC(1:1:1) formation cycling; (c)1MLiPF 6 in EC:EMC:DEC(1:1:1) +2% additive formation cycling; (d) 1MLiPF 6 in EC:EMC:DEC formation cycling and stored at 60 oC for seven days and cycled at C/5 rate for 30cycles; (e) 1MLiPF