Fuel Cells (2^nd Ed.)
Problems and Solutions
The ECS Series of Texts and Monographs Series

The comprehensive, accessible introduction to fuel cells, their applications, and the challenges they pose

Fuel cells—electrochemical energy devices that produce electricity and heat—present a significant opportunity for cleaner, easier, and more practical energy. However, the excitement over fuel cells within the research community has led to such rapid innovation and development that it can be difficult for those not intimately familiar with the science involved to figure out exactly how this new technology can be used. Fuel Cells: Problems and Solutions, Second Edition addresses this issue head on, presenting the most important information about these remarkable power sources in an easy-to-understand way.

Comprising four important sections, the book explores:

• The fundamentals of fuel cells, how they work, their history, and much more

• The major types of fuel cells, including proton exchange membrane fuel cells (PEMFC), direct liquid fuel cells (DLFC), and many others

• The scientific and engineering problems related to fuel cell technology

• The commercialization of fuel cells, including a look at their uses around the world

Now in its second edition, this book features fully revised coverage of the modeling of fuel cells and small fuel cells for portable devices, and all-new chapters on the structural and wetting properties of fuel cell components, experimental methods for fuel cell stacks, and nonconventional design principles for fuel cells, bringing the content fully up to date.

Designed for advanced undergraduate and graduate students in engineering and chemistry programs, as well as professionals working in related fields, Fuel Cells is a compact and accessible introduction to the exciting world of fuel cells and why they matter.

PREFACE TO THE FIRST EDITION xiii

SYMBOLS xv

ABBREVIATIONS AND ACRONYMS xvii

PART I INTRODUCTION 1

Introduction 3

What Is a Fuel Cell? Definition of the Term, 3

Significance of Fuel Cells for the Economy, 3

1 The Working Principles of a Fuel Cell 5

1.1 Thermodynamic Aspects, 5

1.2 Schematic Layout of Fuel Cell Units, 9

1.3 Types of Fuel Cells, 13

1.4 Layout of a Real Fuel Cell: The Hydrogen–Oxygen Fuel Cell with Liquid Electrolyte, 13

1.5 Basic Parameters of Fuel Cells, 18

Reference, 24

2 The Long History of Fuel Cells 25

2.1 The Period Prior to 1894, 25

2.2 The Period from 1894 to 1960, 28

2.3 The Period from 1960 to the 1990s, 31

2.4 The Period After the 1990s, 37

References, 38

PART II MAJOR TYPES OF FUEL CELLS 41

3 Proton-Exchange Membrane Fuel Cells 43

3.1 History of the PEMFC, 44

3.2 Standard PEMFC Version from the 1990s, 47

3.3 Special Features of PEMFC Operation, 51

3.4 Platinum Catalyst Poisoning by Traces of CO in the Hydrogen, 54

3.5 Commercial Activities in Relation to PEMFCs, 56

3.6 Future Development of PEMFCs, 57

3.7 Elevated-Temperature PEMFCs, 64

References, 67

4 Direct Liquid Fuel Cells 71

Part A: Direct Methanol Fuel Cells, 71

4.1 Methanol as a Fuel for Fuel Cells, 71

4.2 Current-Producing Reactions and Thermodynamic Parameters, 72

4.3 Anodic Oxidation of Methanol, 72

4.4 Milestones in DMFC Development, 74

4.5 Membrane Penetration by Methanol (Methanol Crossover), 74

4.6 Varieties of DMFCs, 77

4.7 Special Operating Features of DMFCs, 79

4.8 Practical Models of DMFCs and Their Features, 81

4.9 Problems to Be Solved in Future DMFCs, 83

Part B: Direct Liquid Fuel Cells, 85

4.10 The Problem of Replacing Methanol, 85

4.11 Fuel Cells Using Organic Liquids as Fuels, 86

4.12 Fuel Cells Using Inorganic Liquids as Fuels, 91

References, 94

5 Phosphoric Acid Fuel Cells 99

5.1 Early Work on Phosphoric Acid Fuel Cells, 99

5.2 Special Features of Aqueous Phosphoric Acid Solutions, 100

5.3 Construction of PAFCs, 101

5.4 Commercial Production of PAFCs, 102

5.5 Development of Large Stationary Power Plants, 103

5.6 The Future of PAFCs, 103

5.7 Importance of PAFCs for Fuel Cell Development, 104

References, 105

6 Alkaline Fuel Cells 107

6.1 Hydrogen–Oxygen AFCs, 108

6.2 Alkaline Hydrazine Fuel Cells, 115

6.3 Anion-Exchange (Hydroxyl Ion–Conducting) Membranes, 118

6.4 Methanol Fuel Cells with Anion-Exchange Membranes, 119

6.5 Methanol Fuel Cell with an Invariant Alkaline Electrolyte, 120

6.6 Direct Ammonia Fuel Cell with an Anion-Exchange

Membrane, 121

References, 121

7 Molten Carbonate Fuel Cells 123

7.1 Special Features of High-Temperature Fuel Cells, 123

7.2 Structure of Hydrogen–Oxygen MCFCs, 124

7.3 MCFCs with Internal Fuel Reforming, 126

7.4 Development of MCFC Work, 128

7.5 The Lifetime of MCFCs, 129

References, 131

8 Solid-Oxide Fuel Cells 133

8.1 Schematic Design of Conventional SOFCs, 134

8.2 Tubular SOFCs, 136

8.3 Planar SOFCs, 140

8.4 Monolithic SOFCs, 143

8.5 Varieties of SOFCs, 144

8.6 Utilization of Natural Fuels in SOFCs, 146

8.7 Interim-Temperature SOFCs, 148

8.8 Low-Temperature SOFCs, 152

8.9 Factors Influencing the Lifetime of SOFCs, 154

References, 156

9 Other Types of Fuel Cells 159

9.1 Redox Flow Cells, 159

9.2 Biological Fuel Cells, 162

9.3 Semi-Fuel Cells, 167

9.4 Direct Carbon Fuel Cells, 169

References, 174

10 Fuel Cells and Electrolysis Processes 177

10.1 Water Electrolysis, 177

10.2 Chlor-Alkali Electrolysis, 182

10.3 Electrochemical Synthesis Reactions, 185

References, 187

PART III INHERENT SCIENTIFIC AND ENGINEERING PROBLEMS 189

11 Fuel Management 191

11.1 Reforming of Natural Fuels, 192

11.2 Production of Hydrogen for Autonomous Power Plants, 196

11.3 Purification of Technical Hydrogen, 199

11.4 Hydrogen Transport and Storage, 202

References, 205

12 Electrocatalysis 207

12.1 Fundamentals of Electrocatalysis, 207

12.2 Putting Platinum Catalysts on the Electrodes, 211

12.3 Supports for Platinum Catalysts, 214

12.4 Platinum Alloys and Composites as Catalysts for Anodes, 217

12.5 Nonplatinum Catalysts for Fuel Cell Anodes, 220

12.6 Electrocatalysis of the Oxygen Reduction Reaction, 221

12.7 Stability of Electrocatalysts, 227

References, 228

13 Membranes 233

13.1 Fuel Cell–Related Membrane Problems, 234

13.2 Work to Overcome Degradation of Nafion Membranes, 235

13.3 Modification of Nafion Membranes, 235

13.4 Membranes Made from Polymers Without Fluorine, 237

13.5 Membranes Made from Other Materials, 239

13.6 Matrix-Type Membranes, 239

13.7 Membranes with Hydroxyl Ion Conduction, 240

References, 241

14 Structural and Wetting Properties of Fuel Cell Components 243
Coauthor: Yurij M. Volfkovich

14.1 Methods for Investigating Porous Materials, 244

14.2 A New Method: The Method of Standard Contact Porosimetry, 245

14.3 Catalysts Used in Fuel Cells, 248

14.4 The Catalytic Layer, 252

14.5 The Gas-Diffusion Layer, 254

14.6 Membranes, 257

14.7 Influence of Structural and Wetting Properties on Fuel Cell Performance, 262

References, 264

15 Mathematical Modeling of Fuel Cells 267
Felix N. B¨uchi

15.1 Zero-Dimensional Models, 270

15.2 One-Dimensional Models, 270

15.3 Two-Dimensional Models, 271

15.4 Three-Dimensional Models, 272

15.5 Time Domain, 273

15.6 Concluding Remarks, 273

References, 274

16 Experimental Methods for Investigating Fuel Cell Stacks 275

16.1 Methods Developed Before 2007, 277

16.2 Optical, X-Ray, and EM Methods, 278

16.3 Neutron Beam–Based Methods, 281

16.4 Electrochemical Methods, 283

16.5 Miscellaneous Methods, 286

References, 288

17 Small Fuel Cells for Portable Devices 291

17.1 Special Operating Features of Mini-Fuel Cells, 292

17.2 Flat Mini-Fuel Batteries, 293

17.3 Silicon-Based Mini-Fuel Cells, 296

17.4 PCB-Based Mini-Fuel Cells, 298

17.5 Mini-Solid-Oxide Fuel Cells, 299

17.6 The Problem of Air-Breathing Cathodes, 300

17.7 Prototypes of Power Units with Mini-Fuel Cells, 301

17.8 Concluding Remarks, 304

References, 305

18 Nonconventional Design Principles for Fuel Cells 307

18.1 Conventional Design Principles and Their Drawbacks, 307

18.2 The Principle of Mixed-Reactant Supply: Mixed-Reactant Fuel Cells, 308

18.3 Coplanar Fuel Cell Design: Strip Cells, 310

18.4 The Flow-Through Electrode Principle, 312

18.5 Single-Chamber SOFCs, 313

18.6 Microfluidic Fuel Cells, 319

References, 321

PART IV COMMERCIALIZATION OF FUEL CELLS 325

19 Applications 327

19.1 Large Stationary Power Plants, 327

19.2 Small Stationary Power Units, 332

19.3 Fuel Cells for Transport Applications, 335

19.4 Portables, 341

19.5 Military Applications, 345

19.6 Handicaps Preventing a Broader Commercialization of Fuel Cells, 347

References, 348

20 Fuel Cell Work in Various Countries 351

20.1 Driving Forces for Fuel Cell Work, 351

20.2 Fuel Cells and the Hydrogen Economy, 353

20.3 Activities in North America, 355

20.4 Activities in Europe, 356

20.5 Activities in other Countries, 357

20.6 The Volume of Published Fuel Cell Work, 359

20.7 Legislation and Standardization in the Field of Fuel Cells, 361

References, 362

21 Outlook 363

21.1 Periods of Alternating Hope and Disappointment, 363

21.2 Some Misconceptions, 364
Klaus Müller

21.3 Ideal Fuel Cells, 366

21.4 Projected Future of Fuel Cells, 368

References, 369

GENERAL BIBLIOGRAPHY 371

AUTHOR INDEX 373

SUBJECT INDEX 379

Vladimir S. Bagotsky is an acclaimed scientist in the field of electrochemical phenomena. A former department head at the Moscow Power Sources Institute, where he supervised the development of fuel cells for various national and international projects, including the Sputnik satellites, Dr. Bagotsky also spent twenty years as a department head and principal scientist at the A. N. Frumkin Institute of Physical Chemistry and Electrochemistry. He has published more than 400 papers in scientific journals and in 2010 was acknowledged by the ECS for his sixty-five years spent working in theoretical electrochemistry, electrocatalysis, and applied electrochemistry.