Carbon Nanomaterials for Advanced Energy Systems

With the proliferation of electronic devices, the world will need to double its energy supply by 2050. This book addresses this challenge and discusses synthesis and characterization of carbon nanomaterials for energy conversion and storage.

• Addresses one of the leading challenges facing society today as we steer away from dwindling supplies of fossil fuels and a rising need for electric power due to the proliferation of electronic products
• Promotes the use of carbon nanomaterials for energy applications
• Systematic coverage: synthesis, characterization, and a wide array of carbon nanomaterials are described
• Detailed descriptions of solar cells, electrodes, thermoelectrics, supercapacitors, and lithium-ion-based storage
• Discusses special architecture required for energy storage including hydrogen, methane, etc.

List of Contributors xiii

Preface xvii

PART I Synthesis and characterization of carbon nanomaterials 1

1 Fullerenes, Higher Fullerenes, and their Hybrids: Synthesis, Characterization, and Environmental Considerations 3

1.1 Introduction, 3

1.2 Fullerene, Higher Fullerenes, and Nanohybrids: Structures and Historical Perspective, 5

1.2.1 C60 Fullerene, 5

1.2.2 Higher Fullerenes, 6

1.2.3 Fullerene-Based Nanohybrids, 7

1.3 Synthesis and Characterization, 7

1.3.1 Fullerenes and Higher Fullerenes, 7

1.3.1.1 Carbon Soot Synthesis, 7

1.3.1.2 Extraction, Separation, and Purification, 10

1.3.1.3 Chemical Synthesis Processes, 11

1.3.1.4 Fullerene-Based Nanohybrids, 12

1.3.2 Characterization, 12

1.3.2.1 Mass Spectroscopy, 12

1.3.2.2 NMR, 13

1.3.2.3 Optical Spectroscopy, 13

1.3.2.4 HPLC, 14

1.3.2.5 Electron Microscopy, 14

1.3.2.6 Static and Dynamic Light Scattering, 14

1.4 Energy Applications, 17

1.4.1 Solar Cells and Photovoltaic Materials, 17

1.4.2 Hydrogen Storage Materials, 19

1.4.3 Electronic Components (Batteries, Capacitors, and Open]Circuit Voltage Applications), 20

1.4.4 Superconductivity, Electrical, and Electronic Properties Relevant to Energy Applications, 20

1.4.5 Photochemical and Photophysical Properties Pertinent for Energy Applications, 21

1.5 Environmental Considerations for Fullerene Synthesis and Processing, 21

1.5.1 Existing Environmental Literature for C60, 22

1.5.2 Environmental Literature Status for Higher Fullerenes and NHs, 24

1.5.3 Environmental Considerations, 24

1.5.3.1 Consideration for Solvents, 26

1.5.3.2 Considerations for Derivatization, 26

1.5.3.3 Consideration for Coatings, 27

References, 28

2 Carbon Nanotubes 47

2.1 Synthesis of Carbon Nanotubes, 47

2.1.1 Introduction and Structure of Carbon Nanotube, 47

2.1.2 Arc Discharge and Laser Ablation, 49

2.1.3 Chemical Vapor Deposition, 50

2.1.4 Aligned Growth, 52

2.1.5 Selective Synthesis of Carbon Nanotubes, 57

2.1.6 Summary, 63

2.2 Characterization of Nanotubes, 63

2.2.1 Introduction, 63

2.2.2 Spectroscopy, 63

2.2.2.1 Raman Spectroscopy, 63

2.2.2.2 Optical Absorption (UV]Vis]NIR), 66

2.2.2.3 Photoluminescence Spectroscopy, 68

2.2.3 Microscopy, 70

2.2.3.1 Scanning Tunneling Microscopy and Transmission Electron Microscopy, 70

2.3 Summary, 73

References, 73

3 Synthesis and Characterization of Graphene 85

3.1 Introduction, 85

3.2 Overview of Graphene Synthesis Methodologies, 87

3.2.1 Mechanical Exfoliation, 90

3.2.2 Chemical Exfoliation, 93

3.2.3 Chemical Synthesis: Graphene from Reduced Graphene Oxide, 97

3.2.4 Direct Chemical Synthesis, 102

3.2.5 CVD Process, 102

3.2.5.1 Graphene Synthesis by CVD Process, 103

3.2.5.2 Graphene Synthesis by Plasma CVD Process, 109

3.2.5.3 Grain and GBs in CVD Graphene, 110

3.2.6 Epitaxial Growth of Graphene on SiC Surface, 111

3.3 Graphene Characterizations, 113

3.3.1 Optical Microscopy, 114

3.3.2 Raman Spectroscopy, 116

3.3.3 High Resolution Transmission Electron Microscopy, 118

3.3.4 Scanning Probe Microscopy, 119

3.4 Summary and Outlook, 121

References, 122

4 Doping Carbon Nanomaterials with Heteroatoms 133

4.1 Introduction, 133

4.2 Local Bonding of the Dopants, 135

4.3 Synthesis of Heterodoped Nanocarbons, 137

4.4 Characterization of Heterodoped Nanotubes and Graphene, 139

4.5 Potential Applications, 146

4.6 Summary and Outlook, 152

References, 152

Part II Carbon Na nomaterials For Energy Conversion 163

5 High-Performance Polymer Solar Cells Containing Carbon Nanomaterials 165

5.1 Introduction, 165

5.2 Carbon Nanomaterials as Transparent Electrodes, 167

5.2.1 CNT Electrode, 168

5.2.2 Graphene Electrode, 169

5.2.3 Graphene/CNT Hybrid Electrode, 171

5.3 Carbon Nanomaterials as Charge Extraction Layers, 171

5.4 Carbon Nanomaterials in the Active Layer, 178

5.4.1 Carbon Nanomaterials as an Electron Acceptor, 178

5.4.2 Carbon Nanomaterials as Additives, 180

5.4.3 Donor/Acceptor Functionalized with Carbon Nanomaterials, 183

5.5 Concluding Remarks, 185

Acknowledgments, 185

References, 185

6 Graphene for Energy Solutions and Its Printable Applications 191

6.1 Introduction to Graphene, 191

6.2 Energy Harvesting from Solar Cells, 192

6.2.1 DSSCs, 193

6.2.2 Graphene and DSSCs, 195

6.2.2.1 Counter Electrode, 195

6.2.2.2 Photoanode, 198

6.2.2.3 Transparent Conducting Oxide, 199

6.2.2.4 Electrolyte, 200

6.3 Opv Devices, 200

6.3.1 Graphene and OPVs, 201

6.3.1.1 Transparent Conducting Oxide, 201

6.3.1.2 BHJ, 203

6.3.1.3 Hole Transport Layer, 204

6.4 Lithium-Ion Batteries, 204

6.4.1 Graphene and Lithium-Ion Batteries, 205

6.4.1.1 Anode Material, 205

6.4.1.2 Cathode Material, 209

6.4.2 Li–S and Li–O2 Batteries, 211

6.5 Supercapacitors, 212

6.5.1 Graphene and Supercapacitors, 213

6.6 Graphene Inks, 216

6.7 Conclusions, 219

References, 220

7 Quantum Dot and Heterojunction Solar Cells Containing Carbon Nanomaterials 237

7.1 Introduction, 237

7.2 QD Solar Cells Containing Carbon Nanomaterials, 238

7.2.1 CNTs and Graphene as TCE in QD Solar Cells, 238

7.2.1.1 CNTs as TCE Material in QD Solar Cells, 239

7.2.1.2 Graphene as TCE Material in QD Solar Cells, 240

7.2.2 Carbon Nanomaterials and QD Composites in Solar Cells, 241

7.2.2.1 C60 and QD Composites, 241

7.2.2.2 CNTs and QD Composites, 244

7.2.2.3 Graphene and QD Composites, 245

7.2.3 Graphene QDs Solar Cells, 247

7.2.3.1 Physical Properties of GQDs, 247

7.2.3.2 Synthesis of GQDs, 247

7.2.3.3 PV Devices of GQDs, 247

7.3 Carbon Nanomaterial/Semiconductor Heterojunction Solar Cells, 249

7.3.1 Principle of Carbon/Semiconductor Heterojunction Solar Cells, 249

7.3.2 a-C/Semiconductor Heterojunction Solar Cells, 250

7.3.3 CNT/Semiconductor Heterojunction Solar Cells, 252

7.3.4 Graphene/Semiconductor Heterojunction Solar Cells, 253

7.4 Summary, 261

References, 261

8 Fuel Cell Catalysts Based on Carbon Nanomaterials 267

8.1 Introduction, 267

8.2 Nanocarbon-Supported Catalysts, 268

8.2.1 CNT-Supported Catalysts, 268

8.2.2 Graphene-Supported Catalysts, 271

8.3 Interface Interaction between Pt Clusters and Graphitic Surface, 276

8.4 Carbon Catalyst, 281

8.4.1 Catalytic Activity for ORR, 281

8.4.2 Effect of N-Dope on O2 Adsorption, 283

8.4.3 Effect of N-Dope on the Local Electronic Structure for Pyridinic-N and Graphitic-N, 285

8.4.3.1 Pyridinic-N, 287

8.4.3.2 Graphitic-N, 288

8.4.4 Summary of Active Sites for ORR, 290

References, 291

PART III Carbon nanomaterials for energy storage 295

9 Supercapacitors Based on Carbon Nanomaterials 297

9.1 Introduction, 297

9.2 Supercapacitor Technology and Performance, 298

9.3 Nanoporous Carbon, 304

9.3.1 Supercapacitors with Nonaqueous Electrolytes, 304

9.3.2 Supercapacitors with Aqueous Electrolytes, 311

9.4 Graphene and Carbon Nanotubes, 321

9.5 Nanostructured Carbon Composites, 326

9.6 Other Composites with Carbon Nanomaterials, 327

9.7 Conclusions, 329

References, 330

10 Lithium-Ion Batteries Based on Carbon Nanomaterials 339

10.1 Introduction, 339

10.2 Improving Li-Ion Battery Energy Density, 344

10.3 Improvements to Lithium-Ion Batteries Using Carbon Nanomaterials, 345

10.3.1 Carbon Nanomaterials as Active Materials, 345

10.4 Carbon Nanomaterials as Conductive Additives, 346

10.4.1 Current and SOA Conductive Additives, 346

10.5 Swcnt Additives to Increase Energy Density, 348

10.6 Carbon Nanomaterials as Current Collectors, 351

10.6.1 Current Collector Options, 351

10.7 Implementation of Carbon Nanomaterial Current Collectors for Standard Electrode Composites, 354

10.7.1 Anode: MCMB Active Material, 354

10.7.2 Cathode: NCA Active Material, 356

10.8 Implementation of Carbon Nanomaterial Current Collectors for Alloying Active Materials, 356

10.9 Ultrasonic Bonding for Pouch Cell Development, 358

10.10 Conclusion, 359

References, 362

11 Lithium/Sulfur Batteries Based on Carbon Nanomaterials 365

11.1 Introduction, 365

11.2 Fundamentals of Lithium/Sulfur Cells, 366

11.2.1 Operating Principles, 366

11.2.2 Scientific Problems, 368

11.2.2.1 Dissolution and Shuttle Effect of Lithium Polysulfides, 369

11.2.2.2 Insulating Nature of Sulfur and Li2S, 369

11.2.2.3 Volume Change of the Sulfur Electrode during Cycling, 369

11.2.3 Research Strategy, 369

11.3 Nanostructure Carbon–Sulfur, 370

11.3.1 Porous Carbon–Sulfur Composite, 371

11.3.2 One-Dimensional Carbon–Sulfur Composite, 373

11.3.3 Two-Dimensional Carbon (Graphene)–Sulfur, 375

11.3.4 Three-Dimensional Carbon Paper–Sulfur, 377

11.3.5 Preparation Method of Sulfur–Carbon Composite, 377

11.4 Carbon Layer as a Polysulfide Separator, 380

11.5 Opportunities and Perspectives, 381

References, 382

12 Lithium–air Batteries Based on Carbon Nanomaterials 385

12.1 Metal–Air Batteries, 385

12.2 Li–Air Chemistry, 387

12.2.1 Aqueous Electrolyte Cell, 387

12.2.2 Nonaqueous Aprotic Electrolyte Cell, 389

12.2.3 Mixed Aqueous/Aprotic Electrolyte Cell, 391

12.2.4 All Solid-State Cell, 391

12.3 Carbon Nanomaterials for Li–Air Cells Cathode, 393

12.4 Amorphous Carbons, 393

12.4.1 Porous Carbons, 393

12.5 Graphitic Carbons, 395

12.5.1 Carbon Nanotubes, 395

12.5.2 Graphene, 398

12.5.3 Composite Air Electrodes, 400

12.6 Conclusions, 403

References, 403

13 Carbon-Based Nanomaterials for H2 Storage 407

13.1 Introduction, 407

13.2 Hydrogen Storage in Fullerenes, 408

13.3 Hydrogen Storage in Carbon Nanotubes, 414

13.4 Hydrogen Storage in Graphene-Based Materials, 419

13.5 Conclusions, 427

Acknowledgments, 428

References, 428

Index 439

Wen Lu, PhD, obtained his BSc and MSc from Yunnan University in China and his PhD at the University of Wollongong in Australia. He has been a Senior Research Scientist and Group Leader leading research in multiple research companies in USA. His research activities have been focused on the applications of electrochemistry and advanced materials to the development of a range of electrochemical devices, including energy conversion and storage devices.

Jong-Beom Baek, PhD, is a Professor of the School of Energy and Chemical Engineering/Director of Low-Dimensional Carbon Materials Center (LCMC) in Ulsan National Institute of Science and Technology (UNIST, Korea). He obtained PhD in Polymer Science from the University of Akron (USA). Dr. Baek's current research interests focus on the defect-selective functionalization of carbon-based nanomaterials for application-specific purposes, including energy-related applications.

Liming Dai, PhD, is Case Western Reserve University's Kent Hale Smith Professor in the Department of Macromolecular Science and Engineering. He is also director of the Center of Advanced Science and Engineering for Carbon (Case4Carbon). Dr. Dai received a BSc degree from Zhejiang University, and a PhD from the Australian National University.

Presents state-of-the art synthetic techniques and applications for the use of carbon-based nanomaterials in energy conversion and storage

The world faces the challenge of needing to double its energy supply by 2050. This implies that fossil fuels (oil, coal, natural gas) will be replaced by clean energy sources. For decades, considerable effort has been made to utilize carbon nanomaterials (e.g., fullerenes, carbon nanotubes, graphene) as new energy materials for the development of high-performance energy conversion and storage systems, which are paramount for a wide range of everyday applications. Amid the challenges and opening of new frontiers in nanotechnology, Carbon Nanomaterials for Advanced Energy Systems: Advances in Materials Synthesis and Device Applications focuses on synthesis and characterization of carbon nanomaterials for energy conversion and storage.

The book features:

• Systematic coverage on the synthesis and characterization of a wide array of carbon nanomaterials
• Applications of carbon nanomaterials in solar cells (polymer, dye-sensitized, and quantum dot solar cells), thermoelectrics, fuel cells, supercapacitors, and lithium batteries
• Applications of carbon nanomaterials for energy-related gas storage, including hydrogen and methane
• Detailed descriptions of multidimensional and multifunctional carbon architectures for energy conversion and storage

Addressing one of the leading challenges facing society today as we steer away from dwindling supplies of fossil fuels, and as the need for electric power rises due to the proliferation of electronic products, this book will be useful to graduate students and researchers in the field. It is also a valuable resource for materials scientists, organic and inorganic chemists, physicists, chemical engineers, electrical engineers, device engineers in the discipline.