6.6.1.2 Ladder Circuit Model .......................................... 261
6.6.1.3 Multifactor Electrical Model ............................... 262
6.6.2 Polymer Electrolyte Membrane Fuel Cell Modeling ...... 264
6.6.3 Power Systems Modeling.................................................... 264
6.6.4 Optimization of Models...................................................... 265
6.6.5 Control and Optimization of ESS ...................................... 268
6.6.5.1 Sizing and Costs ................................................... 271
6.7 Improving Dynamic Response and Transient Stability .............. 272
6.8 Summary ............................................................................................ 274
References ..................................................................................................... 274
7. Characterization and Diagnosis Techniques for Electrochemical
Supercapacitors ........................................................................................... 277
7.1 Introduction ....................................................................................... 277
7.2 Electrochemical Cell Design and Fabrication ............................... 278
7.2.1 Conventional Three-Electrode Cell Design and
Fabrication ............................................................................. 278
7.2.2 Two-Electrode Test Cell Design and Assembly ............... 278
7.2.3 Differences between Three- and Two-Electrode Cell
Supercapacitor Characterizations...................................... 280
7.3 Cyclic Voltammetry (CV) ................................................................. 282
7.3.1 Double-Layer Specific Capacitance Characterization
Using Three-Electrode Cell ................................................284
7.3.2 Double-Layer Specific Capacitance Characterization
Using Two-Electrode Test Cell ........................................... 287
7.3.3 Potential Scan Rate Effect on Specific Capacitance ......... 288
7.3.4 Pseudosupercapacitor Characterization by Cyclic
Voltammetry ......................................................................... 289
7.4 Charging–Discharging Curve ......................................................... 291
7.4.1 Capacitance, Maximum Energy and Power
Densities, and Equivalent Series Resistance
Measurements ...................................................................... 292
7.4.2 Cycle Life Measurement Using Charging–
Discharging Curves............................................................. 294
7.5 Electrochemical Impedance Spectroscopy (EIS) .......................... 294
7.5.1 Measurement and Instrumentation .................................. 295
7.5.2
Equivalent Circuits .............................................................. 295
7.5.3 Supercapacitor Data Simulation to Obtain Parameter
Values ..................................................................................... 302
7.6 Physical Characterization of Supercapacitor Materials...............304
7.6.1 Scanning Electron Microscopy (SEM) ..............................304
7.6.2 Transmission Electron Microscopy (TEM) ....................... 306
7.6.3 X-Ray Diffraction (XRD) ..................................................... 307
7.6.4 Energy-Dispersive X-Ray Spectroscopy (EDX) ................308
7.6.5 X-Ray Photoelectron Spectroscopy (XPS) .........................308
x
Contents
6.6.1.3 Multifactor Electrical Model ............................... 262
6.6.2 Polymer Electrolyte Membrane Fuel Cell Modeling ...... 264
6.6.3 Power Systems Modeling.................................................... 264
6.6.4 Optimization of Models...................................................... 265
6.6.5 Control and Optimization of ESS ...................................... 268
6.6.5.1 Sizing and Costs ................................................... 271
6.7 Improving Dynamic Response and Transient Stability .............. 272
6.8 Summary ............................................................................................ 274
References ..................................................................................................... 274
7. Characterization and Diagnosis Techniques for Electrochemical
Supercapacitors ........................................................................................... 277
7.1 Introduction ....................................................................................... 277
7.2 Electrochemical Cell Design and Fabrication ............................... 278
7.2.1 Conventional Three-Electrode Cell Design and
Fabrication ............................................................................. 278
7.2.2 Two-Electrode Test Cell Design and Assembly ............... 278
7.2.3 Differences between Three- and Two-Electrode Cell
Supercapacitor Characterizations...................................... 280
7.3 Cyclic Voltammetry (CV) ................................................................. 282
7.3.1 Double-Layer Specific Capacitance Characterization
Using Three-Electrode Cell ................................................284
7.3.2 Double-Layer Specific Capacitance Characterization
Using Two-Electrode Test Cell ........................................... 287
7.3.3 Potential Scan Rate Effect on Specific Capacitance ......... 288
7.3.4 Pseudosupercapacitor Characterization by Cyclic
Voltammetry ......................................................................... 289
7.4 Charging–Discharging Curve ......................................................... 291
7.4.1 Capacitance, Maximum Energy and Power
Densities, and Equivalent Series Resistance
Measurements ...................................................................... 292
7.4.2 Cycle Life Measurement Using Charging–
Discharging Curves............................................................. 294
7.5 Electrochemical Impedance Spectroscopy (EIS) .......................... 294
7.5.1 Measurement and Instrumentation .................................. 295
7.5.2
Equivalent Circuits .............................................................. 295
7.5.3 Supercapacitor Data Simulation to Obtain Parameter
Values ..................................................................................... 302
7.6 Physical Characterization of Supercapacitor Materials...............304
7.6.1 Scanning Electron Microscopy (SEM) ..............................304
7.6.2 Transmission Electron Microscopy (TEM) ....................... 306
7.6.3 X-Ray Diffraction (XRD) ..................................................... 307
7.6.4 Energy-Dispersive X-Ray Spectroscopy (EDX) ................308
7.6.5 X-Ray Photoelectron Spectroscopy (XPS) .........................308
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Contents