Battery Systems Engineering

Christopher D. Rahn and Chao-Yang WangThe Pennsylvania State University, USA

• 1 Introduction 1 1.1 Energy Storage Applications 11.2 The Role of Batteries 41.3 Battery Systems Engineering 61.4 A Model-Based Approach 91.5 Electrochemical Fundamentals 101.6 Battery Design 121.7 Objectives of this Book 142 Electrochemistry 172.1 Lead-Acid 172.2 Nickel-Metal Hydride 212.3 Lithium-Ion 252.4 Performance Comparison 272.4.1 Energy Density and Specific Energy 272.4.2 Charge and Discharge 312.4.3 Cycle life 342.4.4 Temperature Operating Range 343 Governing Equations 353.1 Thermodynamics and Faraday's Law 353.2 Electrode Kinetics 393.2.1 The Butler-Volmer Equation 403.2.2 Double-Layer Capacitance 423.3 Solid Phase of Porous Electrodes 423.3.1 Ion Transport 443.3.2 Conservation of Charge 453.4 Electrolyte Phase of Porous Electrodes 473.4.1 Ion Transport 473.4.2 Conservation of Charge 523.4.3 Concentrated Solution Theory 543.5 Cell Voltage 543.6 Cell Temperature 553.6.1 Arrhenius Equation 563.6.2 Conservation of Energy 573.7 Side Reactions and Aging 584 Discretization Methods 674.1 Analytical Method 694.1.1 Electrolyte Diffusion 694.1.2 Coupled Electrolyte/Solid Diffusion in Pb Electrodes 794.1.3 Solid State Diffusion in Li-Ion and Ni-MH Particles 814.2 Pade Approximation Method 834.2.1 Solid State Diffusion in Li-Ion Particles 844.3 Integral Method Approximation 854.3.1 Electrolyte Diffusion 854.3.2 Solid State Diffusion in Li-Ion and Ni-MH Particles 884.4 Ritz Method 894.4.1 Electrolyte Diffusion in a Single Domain 894.4.2 Electrolyte Diffusion in Coupled Domains 914.4.3 Coupled Electrolyte/Solid Diffusion in Pb Electrodes 944.5 Finite Element Method 974.5.1 Electrolyte Diffusion 994.5.2 Coupled Electrolyte/Solid Diffusion in Li-Ion Electrodes 1014.6 Finite Difference Method 1024.6.1 Electrolyte Diffusion 1034.6.2 Nonlinear Coupled Electrolyte/Solid Diffusion in Pb Electrodes 1044.7 System Identification in the Frequency Domain 1064.7.1 System Model 1074.7.2 Least Squares Optimization Problem 1074.7.3 Optimization Approach 1094.7.4 Multiple Outputs 1114.7.5 System Identification Toolbox 1124.7.6 Experimental Data 1125 System Response 1155.1 Time Response 1175.1.1 Constant Charge/Discharge 1195.1.2 DST Cycle Response of the Pb-Acid Electrode 1295.2 Frequency Response 1305.2.1 Electrochemical Impedance Spectroscopy 1305.2.2 Discretization Eciency 1375.3 Model Order Reduction 1445.3.1 Truncation Approach 1465.3.2 Grouping Approach 1475.3.3 Frequency Response Curve Fitting 1485.3.4 Performance Comparison 1486 Battery System Models 1596.1 Lead-Acid Battery Model 1606.1.1 Governing Equations 1616.1.2 Discretization Using the Ritz Method 1666.1.3 Numerical Convergence 1706.1.4 Simulation Results 1706.2 Lithium-Ion Battery Model 1736.2.1 Conservation of Species 1786.2.2 Conservation of Charge 1806.2.3 Reaction Kinetics 1816.2.4 Cell Voltage 1826.2.5 Linearization 1826.2.6 Impedance Solution 1846.2.7 FEM Electrolyte Diffusion 1886.2.8 Overall System Transfer Function 1896.2.9 Time Domain Model and Simulation Results 1896.3 Nickel-Metal Hydride Battery Model 1936.3.1 Solid Phase Diffusion 1976.3.2 Conservation of Charge 2006.3.3 Reaction Kinetics 2006.3.4 Cell Voltage 2016.3.5 Simulation Results 2026.3.6 Linearized Model 2037 Estimation 2137.1 State of Charge Estimation 2157.1.1 SOC Modeling 2187.1.2 Instantaneous SOC 2217.1.3 Current Counting Method 2227.1.4 Voltage Lookup Method 2237.1.5 State Estimation 2257.2 Least Squares Model Tuning 2337.2.1 Impedance Transfer Function 2337.2.2 Least Squares Algorithm 2347.2.3 Ni-MH Cell Example 2377.2.4 Identifiability 2397.3 State of Health Estimation 2437.3.1 Parameterization for Environment and Aging 2447.3.2 Parameter Estimation 2457.3.3 Ni-MH Cell Example 2468 Battery Management Systems 2538.1 BMS Hardware 2578.2 Charging Protocols 2608.3 Pulse Power Capability 2648.4 Dynamic Power Limits 2688.5 Pack Management 2728.5.1 Pack Dynamics 2728.5.2 Cell Balancing in Series Strings 2828.5.3 Thermal Management 298Bibliography 308Index 318