5.2.3 Lifetime and Cycle Charging............................................. 205
5.2.4 Polarity .................................................................................. 207
5.2.5 Heat and Temperature Effects ........................................... 207
5.2.6 Humidity............................................................................... 208
5.3 Single Cell Manufacturing .............................................................. 208
5.3.1 Electrode Materials.............................................................. 208
5.3.2 Electrode Fabrication ........................................................... 209
5.3.3 Electrolyte Preparation ....................................................... 209
5.3.4 Current Collector Preparation............................................ 210
5.3.5 Single Cell Structure and Assembly ................................. 210
5.3.5.1 Coin Cells .............................................................. 212
5.3.5.2
Cylindrical Cells ................................................... 212
5.3.5.3 Pouch Cells ............................................................ 213
5.3.6 Considerations for Contact Area and Positioning .......... 214
5.4 Supercapacitor Stack Manufacturing and Construction ............. 216
5.4.1 Cell Stacking to Form Modules ......................................... 216
5.4.2 Utilizing Bipolar Design ..................................................... 217
5.5 Voltage Cell Balancing ...................................................................... 219
5.5.1 Passive Balancing ................................................................. 220
5.5.1.1 Resistance Balancing ........................................... 220
5.5.1.2 Zener Diode Balancing ........................................ 221
5.5.2 Active Balancing .................................................................. 221
5.6 Cell Aging and Voltage Decay ........................................................ 221
5.7 Self Discharging ................................................................................ 224
5.8 Patent Review .................................................................................... 226
5.8.1 Patents on Electrode Materials........................................... 226
5.8.2 Patents on Electrolytes ........................................................ 235
5.8.3 Patents on ES Designs ......................................................... 235
5.9 Major Commercial ES Products ...................................................... 240
5.10 Summary ............................................................................................ 245
References ..................................................................................................... 245
6. Coupling with Batteries and Fuel Cells ................................................. 247
6.1 Introduction ....................................................................................... 247
6.2 Coupling ES Systems with Other Energy Devices ....................... 247
6.3 Hybrid Systems ................................................................................. 248
6.4 Supercapacitor Integration with Batteries ..................................... 250
6.4.1 ES–Battery Direct Coupling: Passive Control .................. 251
6.4.2 ES–Battery Indirect Coupling: Active Control ................ 252
6.4.3 Control Strategies.................................................................254
6.5 Supercapacitor Integration with Fuel Cells ................................... 255
6.6 System Modeling and Optimization .............................................. 257
6.6.1 Supercapacitor Modeling.................................................... 259
6.6.1.1 Classic and Advanced Equivalent Series
Models .................................................................... 260
ix
Contents
5.2.4 Polarity .................................................................................. 207
5.2.5 Heat and Temperature Effects ........................................... 207
5.2.6 Humidity............................................................................... 208
5.3 Single Cell Manufacturing .............................................................. 208
5.3.1 Electrode Materials.............................................................. 208
5.3.2 Electrode Fabrication ........................................................... 209
5.3.3 Electrolyte Preparation ....................................................... 209
5.3.4 Current Collector Preparation............................................ 210
5.3.5 Single Cell Structure and Assembly ................................. 210
5.3.5.1 Coin Cells .............................................................. 212
5.3.5.2
Cylindrical Cells ................................................... 212
5.3.5.3 Pouch Cells ............................................................ 213
5.3.6 Considerations for Contact Area and Positioning .......... 214
5.4 Supercapacitor Stack Manufacturing and Construction ............. 216
5.4.1 Cell Stacking to Form Modules ......................................... 216
5.4.2 Utilizing Bipolar Design ..................................................... 217
5.5 Voltage Cell Balancing ...................................................................... 219
5.5.1 Passive Balancing ................................................................. 220
5.5.1.1 Resistance Balancing ........................................... 220
5.5.1.2 Zener Diode Balancing ........................................ 221
5.5.2 Active Balancing .................................................................. 221
5.6 Cell Aging and Voltage Decay ........................................................ 221
5.7 Self Discharging ................................................................................ 224
5.8 Patent Review .................................................................................... 226
5.8.1 Patents on Electrode Materials........................................... 226
5.8.2 Patents on Electrolytes ........................................................ 235
5.8.3 Patents on ES Designs ......................................................... 235
5.9 Major Commercial ES Products ...................................................... 240
5.10 Summary ............................................................................................ 245
References ..................................................................................................... 245
6. Coupling with Batteries and Fuel Cells ................................................. 247
6.1 Introduction ....................................................................................... 247
6.2 Coupling ES Systems with Other Energy Devices ....................... 247
6.3 Hybrid Systems ................................................................................. 248
6.4 Supercapacitor Integration with Batteries ..................................... 250
6.4.1 ES–Battery Direct Coupling: Passive Control .................. 251
6.4.2 ES–Battery Indirect Coupling: Active Control ................ 252
6.4.3 Control Strategies.................................................................254
6.5 Supercapacitor Integration with Fuel Cells ................................... 255
6.6 System Modeling and Optimization .............................................. 257
6.6.1 Supercapacitor Modeling.................................................... 259
6.6.1.1 Classic and Advanced Equivalent Series
Models .................................................................... 260
ix
Contents