Wayne State University Wayne State University Dissertations 1-1-2016 Computational Modeling Of High-Performance Nickel-Metal Hydride Battery Materials Diana Felicia Wong Wayne State University, Follow this and additional works at: http://digitalcommons.wayne.edu/oa_dissertations Part of the Chemical Engineering Commons Recommended Citation Wong, Diana Felicia, "Computational Modeling Of High-Performance Nickel-Metal Hydride Battery Materials" (2016). Wayne State University Dissertations. Paper 1494. This Open Access Dissertation is brought to you for free and open access by DigitalCommons@WayneState. It has been accepted for inclusion in Wayne State University Dissertations by an authorized administrator of DigitalCommons@WayneState. COMPUTATIONAL MODELING OF HIGH-PERFORMANCE NICKEL-METAL HYDRIDE BATTERY MATERIALS by DIANA F. WONG DISSERTATION Submitted to the Graduate School of Wayne State University, Detroit, Michigan in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY 2016 MAJOR: CHEMICAL ENGINEERING Approved By: ____________________________________ Advisor Date ____________________________________ Advisor Date ____________________________________ ____________________________________ ____________________________________ © COPYRIGHT BY DIANA F. WONG 2016 All Rights Reserved DEDICATION To my family and friends and their unconditional love and support. ii ACKNOWLEDGMENTS I would like to thank my advisors Dr. K.Y. Simon Ng and Dr. Kwo-Hsiung Young for their steadfast encouragement and support of not only this work, but of my academic and professional career. They have provided valuable insights and perspectives in tackling problems large and small, always reminding me to keep the big picture in mind. I am grateful to Dr. Eranda Nikolla, Dr. Da Deng, and Dr. Mark Cheng for serving on my committee, contributing their time and expertise to help mold and strengthen the work presented in this dissertation. I would like to thank Mr. Michael Fetcenko, Vice President and Managing Director of BASF Battery Materials – Ovonic, for his kind support and encouragement towards advancing my academic and professional training. I am also grateful to Dr. Baoquan Huang, Dr. Jean Nei, Dr. Benjamin Chao, Dr. Benjamin Reichman, Dr. Lixin Wang, Mr. Taihei Ouchi, Ms. Su Cronogue, Dr. Tiejun Meng, Dr. Shuli Yan, Dr. Negar Mosavati, Mr. William Mays, Ms. Rose Bertolini, Mr. James Strebe, Ms. Sherry Hu, Mr. David Pawlik, Mr. Ryan Blankenship, Mr. Alan Chan and the rest of my colleagues at BASF Battery Materials – Ovonic and Wayne State University. They’ve generously shared with me their time, support, expertise, and guidance. I would also like to thank my family for their unconditional support and understanding. My brother, Gary S. Wong, also provided a sounding ear and valuable advice for everything programming related. Thank you. iii TABLE OF CONTENTS Dedication ....................................................................................................................................... ii Acknowledgments.......................................................................................................................... iii List of Tables ............................................................................................................................... viii List of Figures ................................................................................................................................ ix CHAPTER 1. Introduction ........................................................................................................... 1 1.1 Significance of Research .................................................................................................. 2 CHAPTER 2. Background and Theory ........................................................................................ 5 2.1 Nickel-Metal Hydride Battery .......................................................................................... 5 2.1.1 C14 and C15 Laves Phase AB2 Anode Materials ..................................................... 7 2.1.2 Nickel Hydroxide Cathode Materials ..................................................................... 12 2.2 Density Functional Theory ............................................................................................. 23 2.2.1 Born-Oppenheimer Approximation ........................................................................ 23 2.2.2 Schrödinger Equation.............................................................................................. 24 2.2.3 Thomas-Fermi-Dirac Approximation ..................................................................... 25 2.2.4 Hohenberg-Kohn Theorems.................................................................................... 26 2.2.5 Kohn-Sham Equations ............................................................................................ 27 2.2.6 Exchange-Correlation Functionals.......................................................................... 28 2.2.7 Ground State Structure and Energy of Formation .................................................. 29 2.3 Materials Characterization Techniques and Modeling ................................................... 29 iv 2.3.1 X-Ray Diffraction ................................................................................................... 30 2.3.2 Electrochemical Impedance Spectroscopy ............................................................. 33 CHAPTER 3. Computational Study of C14/C15 Laves Phase Mg(Cu1-xZnx)2 Alloys ............. 40 3.1 Background .................................................................................................................... 40 3.2 Computational Methods ................................................................................................. 43 3.3 Results and Discussion ................................................................................................... 45 3.3.1 Convergence ........................................................................................................... 45 3.3.2 Bulk Parameters ...................................................................................................... 46 3.3.3 MgCu2 and MgZn2 Binary Alloys .......................................................................... 47 3.3.4 Mg(Cu1-xZnx)2 Structures ........................................................................................ 49 3.4 Summary ........................................................................................................................ 50 CHAPTER 4. Structure and PCT Hysteresis in LaNi5 and TiMn2 Alloys ................................. 52 4.1 Background .................................................................................................................... 52 4.2 Crystal Structure ............................................................................................................. 55 4.3 Computational Methods ................................................................................................. 56 4.4 Results and Discussion ................................................................................................... 56 4.4.1 Relative Lattice Expansion vs. c/a Ratio ................................................................ 62 4.4.2 Effect of Anisotropy ............................................................................................... 64 4.4.3 Effect of Hydrogen Insertion Site ........................................................................... 69 4.4.4 Average Electron Concentration ............................................................................. 70 v 4.4.5 Initial Factors vs. Dynamic Factors ........................................................................ 71 4.5 Summary ........................................................................................................................ 72 CHAPTER 5. Stacking Faults in Nickel Hydroxide Spherical Powders ................................... 74 5.1 Background .................................................................................................................... 75 5.2 Experimental Setup ........................................................................................................ 76 5.3 Structure Refinement...................................................................................................... 77 5.4 Results and Discussion ................................................................................................... 78 5.4.1 Effect of Structural Disorder on the (101) Crystallite Size ..................................... 85 5.4.2 Deformation Faults vs. Growth Faults .................................................................... 86 5.4.3 Evolution of Stacking Faults over Precipitation Time ............................................ 88 5.5 Summary ........................................................................................................................ 91 CHAPTER 6. Effects of La and Nd on Surface Reactions in Laves Phase AB2 Alloys ............ 93 6.1 Background .................................................................................................................... 93 6.2 Experimental Setup ........................................................................................................ 94 6.3 Results and Discussion ................................................................................................... 95 6.3.1 La Addition ............................................................................................................