Electrochemical supercapacitors for energy storage and delivery : fundamentals and applications

377 Pages·2013·32.07 MB·English

by  Aiping Yu

Chemical Engineering
ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION
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ELECTROCHEMICAL SUPERCAPACITORS L
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FOR ENERGY STORAGE AND DELIVERY
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FUNDAMENTALS AND APPLICATIONS N R
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Although recognized as an important component of all energy storage and con- G H
version technologies, electrochemical supercapacitators (ES) still face develop- Y E
ment challenges in order to reach their full potential. A thorough examination of M
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development in the technology during the past decade, Electrochemical Super-
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capacitors for Energy Storage and Delivery: Fundamentals and Applications C
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provides a comprehensive introduction to the ES from technical and practical A
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aspects and crystallization of the technology, detailing the basics of ES as well as L
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its components and characterization techniques.
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The book illuminates the practical aspects of understanding and applying the E
technology within the industry and provides sufficient technical detail of newer P
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materials being developed by experts in the field which may surface in the future.
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The book discusses the technical challenges and the practical limitations and
their associated parameters in ES technology. It also covers the structure and D C
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options for device packaging and materials choices such as electrode materials,
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electrolyte, current collector, and sealants based on comparison of available data.
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Features C
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• Features the most recent advances made in supercapacitors V I
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• Discusses cutting-edge nanotechnology
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• Includes theoretical calculation and modeling that can be used to guide and R
promote materials as well as technology development Y R
• Step by step demonstrations of how to fabricate supercapacitors, testing, S

and characterization
• Contains contributions from international leading scientists active in
supercapacitor research and manufacturing
• Provides invaluable information that will benefit readers from both academia
and industry
Supplying an in depth understanding of the components, design, and character-
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ization of electrochemical supercapacitors, the book has wide-ranging appeal to a
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K13215 Aiping Yu, Victor Chabot,
and Jiujun Zhang
K13215_Cover.indd 1 2/22/13 10:59 AM

ELECTROCHEMICAL
SUPERCAPACITORS FOR
ENERGY STORAGE
AND DELIVERY
FUNDAMENTALS AND APPLICATIONS
ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION
Series Editor: Jiujun Zhang
National Research Council Institute for Fuel Cell Innovation
Vancouver, British Columbia, Canada
Published Titles
Electrochemical Supercapacitors for Energy Storage and Delivery: Fundamentals and Applications
Aiping Yu, Victor Chabot, and Jiujun Zhang
Forthcoming Titles
Electrochemical Polymer Electrolyte Membranes
Yan-Jie Wang, David P. Wilkinson, and Jiujun Zhang
Lithium-Ion Batteries: Fundamentals and Applications
Yuping Wu
Proton Exchange Membrane Fuel Cells
Zhigang Qi
Solid Oxide Fuel Cells: From Fundamental Principles to Complete Systems
Radenka Maric
ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION
ELECTROCHEMICAL
SUPERCAPACITORS FOR
ENERGY STORAGE
AND DELIVERY
FUNDAMENTALS AND APPLICATIONS
Aiping Yu, Victor Chabot,
and Jiujun Zhang
CRC Press
Taylor & Francis Group
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Boca Raton, FL 33487-2742
© 2013 by Taylor & Francis Group, LLC
CRC Press is an imprint of Taylor & Francis Group, an Informa business
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Version Date: 20121030
International Standard Book Number-13: 978-1-4398-6990-1 (eBook - PDF)
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Contents
Series Preface .......................................................................................................xiii
Preface .....................................................................................................................xv
Authors ................................................................................................................xvii
1. Fundamentals of Electric Capacitors ..........................................................1
1.1 Introduction ...........................................................................................1
1.1.1 History .......................................................................................1
1.2 Electric Charge, Electric Field, and Electric Potential and
Their Implications for Capacitor Cell Voltage ...................................2
1.2.1 Electric Charge .........................................................................2
1.2.2 Electric Field and Potential .....................................................4
1.2.3 Implication of Electric Potential in Capacitor Cell
Voltage ....................................................................................5
1.3 Capacitance Definition and Calculation ............................................6
1.3.1 Dielectric Materials and Constants .......................................9
1.3.1.1 Dielectric Polarization Mechanisms ....................11
1.3.1.2 Ceramic Dielectrics and Their Capacitors ..........11
1.3.1.3 Electrolytic Dielectrics and Their Capacitors .....12
1.3.1.4 Paper and Polymer Dielectrics and Their
Capacitors ................................................................13
1.3.1.5 Classification of Dielectric Materials ...................13
1.4 Capacitor Charging and Recharging Processes .............................15
1.4.1 DC and AC Currents .............................................................15
1.4.2 Charging of Capacitor: RC Time .........................................17
1.4.3 Discharge of Capacitor ..........................................................18
1.5 Energy Storage in Capacitor ..............................................................20
1.6 Capacitor Containing Electrical Circuits and Corresponding
Calculation ...........................................................................................21
1.6.1 Circuit Resistors .....................................................................21
1.6.2 Circuit Capacitors ..................................................................21
1.6.3 Inductors .................................................................................23
1.6.4 Resistor–Inductor Circuits ....................................................23
1.6.5 Inductor–Capacitor Circuits .................................................25
1.6.5 Resistor–Inductor–Capacitor Circuits .................................26
1.6.6 Resistive, Capacitive, and Inductive Loads for AC
Circuits ....................................................................................27
1.6.6.1 Series Resistor–Inductor–Capacitor Circuit .......28
1.6.6.2 RLC Circuits Having Other R, L, and C
Combinations ..........................................................31
v
vi Contents
1.7 Types and Structures of Capacitors ..................................................32
1.7.1 Fixed Capacitors .....................................................................32
1.7.2 Variable Capacitors ................................................................32
1.7.3 Power Capacitors ....................................................................33
1.7.4 High-Voltage Capacitors .......................................................33
1.7.5 Interference-Suppression Capacitors ..................................33
1.7.6 Ferrodielectric Capacitors .....................................................34
1.7.7 Polar Polymer Dielectric Capacitors ....................................34
1.7.8 Linear and Nonlinear Capacitors ........................................34
1.8 Summary ..............................................................................................34
References .......................................................................................................35
2. Fundamentals of Electrochemical Double-Layer Supercapacitors.....37
2.1 Introduction .........................................................................................37
2.2 Electrode and Electrolyte Interfaces and Their Capacitances ......38
2.2.1 Electric Double-Layer at Interface of Electrode and
Electrolyte Solution ................................................................39
2.2.2 Double-Layer Net Charge Density by Gouy–
Chapman–Stern (GCS) Modeling ........................................45
2.2.3 Theoretical Differential Capacitance of Electric
Double-Layer ..........................................................................47
2.2.4 Differential Capacitance of Entire Double-Layer ..............48
2.2.5 Potential Drop Distribution within Electric Double-
Layer ........................................................................................50
2.2.6 Factors Affecting Double-Layer Capacitance ....................51
2.2.7 Specific Adsorption of Ions and Effect on Double-Layer .52
2.3 Electrode Potential and Double-Layer Potential Windows
Using Different Electrode Materials and Electrolytes ...................54
2.3.1 Electrode Potential .................................................................54
2.3.2 Double-Layer Potential Ranges or Windows .....................56
2.4 Capacitance of Porous Carbon Materials.........................................58
2.4.1 Carbon Particles and Their Associated Electrode Layers 59
2.4.2 Capacitances of Porous Carbon Materials and Their
Associated Electrode Layers ................................................61
2.5 Electrochemical Double-Layer Supercapacitors .............................62
2.5.1 Structure and Capacitance ...................................................62
2.5.2 Equivalent Series Resistance (ESR) .....................................64
2.5.2.1 Thermal Degradation from ESR...........................65
2.5.3 Leakage Resistance ................................................................66
2.5.3.1 Self Discharge through Leakage Mechanisms ..67
2.5.4 Supercapacitor Charging and Discharging .......................69
2.5.4.1 Charging at Constant Cell Voltage ......................69
2.5.4.2 Charging at Constant Cell Current .....................70
2.5.4.3 Discharging Supercapacitor Cell at
Constant Resistance ...............................................72
Contents vii
2.5.4.4 Discharging Supercapacitor Cell at
Constant Voltage .....................................................73
2.5.4.5 Discharging Supercapacitor Cell at
Constant Current ....................................................74
2.5.4.6 Charging and Discharging Curves at
Constant Current ....................................................76
2.5.4.7 AC Impedance Equivalent Circuit .......................79
2.6 Energy and Power Densities of Electrochemical
Supercapacitors ....................................................................................79
2.6.1 Energy Densities ....................................................................79
2.6.2 Power Densities ......................................................................81
2.6.3 Ragone Plot: Relationship of Energy Density and
Power Density ........................................................................86
2.7 Supercapacitor Stacking .....................................................................89
2.7.1 Stacking in Series ...................................................................89
2.7.2 Stacking in Parallel ................................................................90
2.8 Double-Layer Supercapacitors versus Batteries ..............................91
2.9 Applications of Supercapacitors ........................................................93
2.10 Summary ..............................................................................................95
References .......................................................................................................95
3. Fundamentals of Electrochemical Pseudocapacitors ............................99
3.1 Introduction .........................................................................................99
3.2 Electrochemical Pseudocapacitance of Electrode–Electrolyte
Interface ..............................................................................................102
3.2.1 Fundamental Electrochemistry of Pseudocapacitance ..102
3.2.2 Pseudocapacitance Induced by Underpotential
Deposition .............................................................................108
3.2.3 Pseudocapacitance Induced by Lithium Intercalation ...112
3.2.4 Pseudocapacitance Induced by Redox Couples ...............113
3.2.4.1 Pseudocapacitance Induced by Dissolved
Couples ..................................................................113
3.2.4.2 Pseudocapacitance Induced by Undissolved
Redox Couples ......................................................115
3.2.5 Pseudocapacitance Induced in Electrically
Conducting Polymer (ECP) ................................................120
3.2.6 Coupling of Differential Double-Layer and
Pseudocapacitance ...............................................................121
3.3 Electrochemical Impedance Spectroscopy and Equivalent
Circuits ...............................................................................................124
3.4 Materials, Electrodes, and Cell Designs ........................................126
3.4.1 Electrode Materials ..............................................................126
3.4.2 Cell Designs (Symmetric versus Asymmetric) ................129
3.5 Summary ............................................................................................131
References .....................................................................................................132
viii Contents
4. Components and Materials for Electrochemical Supercapacitors....135
4.1 Introduction .......................................................................................135
4.1.1 Traditional Capacitors .........................................................135
4.1.2 Electrochemical Supercapacitors .......................................136
4.2 Anode and Cathode Structures and Materials .............................137
4.2.1 Overview of Battery Functions and Materials ................137
4.2.2 Introducing Electrode Requirements for
Electrochemical Supercapacitors .......................................142
4.2.3 Electrode Conductivity .......................................................143
4.2.4 Surface Area for EDLC Design ..........................................143
4.2.5 Pore Structure for EDLC Design........................................144
4.2.6 Functionalization Effects on EDLCs .................................146
4.2.7 Series Resistance in EDLC Design.....................................150
4.2.8 EDLC Electrode Materials ..................................................151
4.2.8.1 Activated Carbons ................................................151
4.2.8.2 Templated Active Carbons ..................................153
4.2.8.3 Carbon Nanotubes ...............................................156
4.2.8.4 Carbon Onions......................................................160
4.2.8.5 Graphene ...............................................................161
4.2.8.6 Carbon Nanofibers ...............................................165
4.2.9 Pseudocapacitive Materials ................................................166
4.2.9.1 Storage Overview .................................................166
4.2.9.2 Transition Metal Oxides ......................................167
4.2.9.3 Transition Metal Nitrides ....................................171
4.2.9.4 Conducting Polymers ..........................................173
4.2.10 Asymmetric Structures .......................................................177
4.3 Electrolyte Structures and Materials ..............................................180
4.3.1 Electrolyte Overview ...........................................................180
4.3.1.1 Electrolyte Decomposition ..................................181
4.3.2 Aqueous Electrolytes ...........................................................182
4.3.3 Organic Electrolytes ............................................................183
4.3.4 Ionic Liquids .........................................................................184
4.3.5 Solid State Polymer Electrolytes ........................................185
4.4 Separator Structures .........................................................................189
4.5 Current Collectors .............................................................................190
4.6 Sealants ...............................................................................................192
4.7 Summary ............................................................................................194
References .....................................................................................................194
5. Electrochemical Supercapacitor Design, Fabrication, and
Operation ......................................................................................................203
5.1 Introduction .......................................................................................203
5.2 Design Considerations .....................................................................204
5.2.1 Cell Voltage ...........................................................................204
5.2.2 Frequency Response ............................................................205