Supercapacitors -- Contents -- Series Editor Preface -- Preface -- About the Series Editor -- About the Volume Editors -- List of Contributors -- 1 General Principles of Electrochemistry -- 1.1 Equilibrium Electrochemistry -- 1.1.1 Spontaneous Chemical Reactions -- 1.1.2 The Gibbs Energy Minimum -- 1.1.3 Bridging the Gap between Chemical Equilibrium and Electrochemical Potential -- 1.1.4 The Relation between E and DGr -- 1.1.5 The Nernst Equation -- 1.1.6 Cells at Equilibrium -- 1.1.7 Standard Potentials -- 1.1.8 Using the Nernst Equation - Eh-pH Diagrams -- 1.2 Ionics -- 1.2.1 Ions in Solution -- 1.2.1.1 Ion-Solvent Interactions -- 1.2.1.2 Thermodynamics -- 1.2.2 The Born or Simple Continuum Model -- 1.2.2.1 Testing the Born Equation -- 1.2.3 The Structure of Water -- 1.2.3.1 Water Structure near an Ion -- 1.2.3.2 The Ion-Dipole Model -- 1.2.3.3 Cavity Formation -- 1.2.3.4 Breaking up the Cluster -- 1.2.3.5 Ion-Dipole Interaction -- 1.2.3.6 The Born Energy -- 1.2.3.7 Orienting the Solvated Ion in the Cavity -- 1.2.3.8 The Leftover Water Molecules -- 1.2.3.9 Comparison with Experiment -- 1.2.3.10 The Ion-Quadrupole Model -- 1.2.3.11 The Induced Dipole Interaction -- 1.2.3.12 The Results -- 1.2.3.13 Enthalpy of Hydration of the Proton -- 1.2.4 The Solvation Number -- 1.2.4.1 Coordination Number -- 1.2.4.2 The Primary Solvation Number -- 1.2.5 Activity and Activity Coefficients -- 1.2.5.1 Fugacity (f') -- 1.2.5.2 Dilute Solutions of Nonelectrolytes -- 1.2.5.3 Activity (a) -- 1.2.5.4 Standard States -- 1.2.5.5 Infinite Dilution -- 1.2.5.6 Measurement of Solvent Activity -- 1.2.5.7 Measurement of Solute Activity -- 1.2.5.8 Electrolyte Activity -- 1.2.5.9 Mean Ion Quantities -- 1.2.5.10 Relation between f, y, andy -- 1.2.6 Ion-Ion Interactions -- 1.2.6.1 Introduction -- 1.2.6.2 Debye-Huckel Model for Calculating o2.

1.2.6.3 Poisson-Boltzmann Equation -- 1.2.6.4 Charge Density -- 1.2.6.5 Solving the Poisson-Boltzmann Equation -- 1.2.6.6 Calculation of D ui-I -- 1.2.6.7 Debye Length, K-1 or LD -- 1.2.6.8 The Activity Coefficient -- 1.2.6.9 Comparison with Experiment -- 1.2.6.10 Approximations of the Debye-Huckel Limiting Law -- 1.2.6.11 The Distance of Closest Approach -- 1.2.6.12 Physical Interpretation of the Activity Coefficient -- 1.2.7 Concentrated Electrolyte Solutions -- 1.2.7.1 The Stokes-Robinson Treatment -- 1.2.7.2 The Ion-Hydration Correction -- 1.2.7.3 The Concentration Correction -- 1.2.7.4 The Stokes-Robinson Equation -- 1.2.7.5 Evaluation of the Stokes-Robinson Equation -- 1.2.8 Ion Pair Formation -- 1.2.8.1 Ion Pairs -- 1.2.8.2 The Fuoss Treatment -- 1.2.9 Ion Dynamics -- 1.2.9.1 Ionic Mobility and Transport Numbers -- 1.2.9.2 Diffusion -- 1.2.9.3 Fick's Second Law -- 1.2.9.4 Diffusion Statistics -- 1.3 Dynamic Electrochemistry -- 1.3.1 Review of Fundamentals -- 1.3.1.1 Potential -- 1.3.1.2 Potential inside a Good Conductor -- 1.3.1.3 Charge on a Good Conductor -- 1.3.1.4 Force between Charges -- 1.3.1.5 Potential due to an Assembly of Charges -- 1.3.1.6 Potential Difference between Two Phases in Contact (Do) -- 1.3.1.7 The Electrochemical Potential (u) -- 1.3.2 The Electrically Charged Interface or Double Layer -- 1.3.2.1 The Interface -- 1.3.2.2 Ideally Polarized Electrode -- 1.3.2.3 The Helmholtz Model -- 1.3.2.4 Gouy-Chapman or Diffuse Model -- 1.3.2.5 The Stern Model -- 1.3.2.6 The Bockris, Devanathan, and Muller Model -- 1.3.2.7 Calculation of the Capacitance -- 1.3.3 Charge Transfer at the Interface -- 1.3.3.1 Transition State Theory -- 1.3.3.2 Redox Charge-Transfer Reactions -- 1.3.3.3 The Act of Charge Transfer -- 1.3.3.4 The Butler-Volmer Equation -- 1.3.3.5 I in Terms of the Standard Rate Constant (k0).

1.3.3.6 Relation between k0 and I0 -- 1.3.4 Multistep Processes -- 1.3.4.1 The Multistep Butler-Volmer Equation -- 1.3.4.2 Rules for Mechanisms -- 1.3.4.3 Concentration Dependence of I0 -- 1.3.4.4 Charge-Transfer Resistance (Rct) -- 1.3.4.5 Whole Cell Voltages -- 1.3.5 Mass Transport Control -- 1.3.5.1 Diffusion and Migration -- 1.3.5.2 The Limiting Current Density (IL) -- 1.3.5.3 Rotating Disk Electrode -- Further Reading -- 2 General Properties of Electrochemical Capacitors -- 2.1 Introduction -- 2.2 Capacitor Principles -- 2.3 Electrochemical Capacitors -- 2.3.1 Electric Double-Layer Capacitors -- 2.3.1.1 Double-Layer and Porous Materials Models -- 2.3.1.2 EDLC Construction -- 2.3.2 Pseudocapacitive Electrochemical Capacitors -- 2.3.2.1 Electronically Conducting Polymers -- 2.3.2.2 Transition Metal Oxides -- 2.3.2.3 Lithium-Ion Capacitors -- 2.4 Summary -- Acknowledgments -- References -- 3 Electrochemical Techniques -- 3.1 Electrochemical Apparatus -- 3.2 Electrochemical Cell -- 3.3 Electrochemical Interface: Supercapacitors -- 3.4 Most Used Electrochemical Techniques -- 3.4.1 Transient Techniques -- 3.4.1.1 Cyclic Voltammetry -- 3.4.1.2 Galvanostatic Cycling -- 3.4.2 Stationary Technique -- 3.4.2.1 Electrochemical Impedance Spectroscopy -- 3.4.2.2 Supercapacitor Impedance -- References -- 4 Electrical Double-Layer Capacitors and Carbons for EDLCs -- 4.1 Introduction -- 4.2 The Electrical Double Layer -- 4.3 Types of Carbons Used for EDLCs -- 4.3.1 Activated Carbon Powders -- 4.3.2 Activated Carbon Fabrics -- 4.3.3 Carbon Nanotubes -- 4.3.4 Carbon Aerogels -- 4.4 Capacitance versus Pore Size -- 4.5 Evidence of Desolvation of Ions -- 4.6 Performance Limitation: Pore Accessibility or Saturation of Porosity -- 4.6.1 Limitation by Pore Accessibility -- 4.6.2 Limitation of Capacitor Performance by Porosity Saturation.

4.7 Beyond the Double-Layer Capacitance in Microporous Carbons -- 4.7.1 Microporous Carbons in Neat Ionic Liquid Electrolyte -- 4.7.2 Extra Capacitance with Ionic Liquids in Solution -- 4.7.3 Ions Trapping in Pores -- 4.7.4 Intercalation/Insertion of Ions -- 4.8 Conclusions -- References -- 5 Modern Theories of Carbon-Based Electrochemical Capacitors -- 5.1 Introduction -- 5.1.1 Carbon-Based Electrochemial Capacitors -- 5.1.2 Elements of EDLCs -- 5.2 Classical Theories -- 5.2.1 Compact Layer at the Interface -- 5.2.2 Diffuse Layer in the Electrolyte -- 5.2.3 Space Charge Layer in the Electrodes -- 5.3 Recent Developments -- 5.3.1 Post-Helmholtz Models with Surface Curvature Effects -- 5.3.1.1 Models for Endohedral Capacitors -- 5.3.1.2 Models for Hierarchically Porous Carbon Materials -- 5.3.1.3 Models for Exohedral Capacitors -- 5.3.2 EDL Theories Beyond the GCS Model -- 5.3.3 Quantum Capacitance of Graphitic Carbons -- 5.3.4 Molecular Dynamics Simulations -- 5.3.4.1 EDLs in Aqueous Electrolytes -- 5.3.4.2 EDLs in Organic Electrolytes -- 5.3.4.3 EDLs in Room-Temperature ILs -- 5.4 Concluding Remarks -- Acknowledgments -- References -- 6 Electrode Materials with Pseudocapacitive Properties -- 6.1 Introduction -- 6.2 Conducting Polymers in Supercapacitor Application -- 6.3 Metal Oxide/Carbon Composites -- 6.4 Pseudocapacitive Effect of Heteroatoms Present in the Carbon Network -- 6.4.1 Oxygen-Enriched Carbons -- 6.4.2 Nitrogen-Enriched Carbons -- 6.5 Nanoporous Carbons with Electrosorbed Hydrogen -- 6.6 Electrolytic Solutions - a Source of Faradaic Reactions -- 6.7 Conclusions - Profits and Disadvantages of Pseudocapacitive Effects -- References -- 7 Li-Ion-Based Hybrid Supercapacitors in Organic Medium -- 7.1 Introduction -- 7.2 Voltage Limitation of Conventional EDLCs -- 7.3 Hybrid Capacitor Systems -- 7.3.1 Lithium-Ion Capacitor (LIC).

7.3.2 Nanohybrid Capacitor (NHC) -- 7.4 Material Design for NHC -- 7.5 Conclusion -- Abbreviations -- References -- 8 Asymmetric and Hybrid Devices in Aqueous Electrolytes -- 8.1 Introduction -- 8.2 Aqueous Hybrid (Asymmetric) Devices -- 8.2.1 Principles, Requirements, and Limitations -- 8.2.2 Activated Carbon/PbO2 Devices -- 8.2.3 Activated Carbon/Ni(OH)2 Hybrid Devices -- 8.2.4 Aqueous-Based Hybrid Devices Based on Activated Carbon and Conducting Polymers -- 8.3 Aqueous Asymmetric Electrochemical Capacitors -- 8.3.1 Principles, Requirements, and Limitations -- 8.3.2 Activated Carbon/MnO2 Devices -- 8.3.3 Other MnO2-Based Asymmetric or Hybrid Devices -- 8.3.4 Carbon/Carbon Aqueous Asymmetric Devices -- 8.3.5 Carbon/RuO2 Devices -- 8.4 Tantalum Oxide-Ruthenium Oxide Hybrid Capacitors -- 8.5 Perspectives -- References -- 9 EDLCs Based on Solvent-Free Ionic Liquids -- 9.1 Introduction -- 9.2 Carbon Electrode/Ionic Liquid Interface -- 9.3 Ionic Liquids -- 9.4 Carbon Electrodes -- 9.5 Supercapacitors -- 9.6 Concluding Remarks -- Ionic Liquid Codes -- Glossary -- References -- 10 Manufacturing of Industrial Supercapacitors -- 10.1 Introduction -- 10.2 Cell Components -- 10.2.1 Electrode Design and Its Components -- 10.2.1.1 Current Collector -- 10.2.1.2 Activated Carbons for Supercapacitors -- 10.2.1.3 Industrial Activated Carbons for Industrial Supercapacitors -- 10.2.1.4 Particle Size Distribution of Activated Carbons and Its Optimization -- 10.2.1.5 Binders -- 10.2.1.6 Conductive Additives -- 10.2.2 Electrolyte -- 10.2.2.1 Electrolyte Impact on Performance -- 10.2.2.2 Liquid-State Electrolyte and Remaining Problems -- 10.2.2.3 Ionic Liquid Electrolyte -- 10.2.2.4 Solid-State Electrolyte -- 10.2.3 Separator -- 10.2.3.1 Separator Requirements -- 10.2.3.2 Cellulosic Separators and Polymeric Separators -- 10.3 Cell Design -- 10.3.1 Small-Size Components.

10.3.2 Large Cells.