Our energy-hungry world increasingly relies on new methods to store and convert energy for portable electronics, as well as environmentally friendly modes of transportation and electrical energy generation. The development of high-performance power sources are intimately linked to the availability of advanced materials. Designing batteries and capacitors with higher specific energy and power, longer cycle life and rapid charge/discharge rates requires a deeper understanding of the relationship between materials properties and performance. Fuel cells, which offer the potential for clean, efficient conversion of chemical energy to electrical energy, are hampered by high cost and performance problems which can be resolved by new materials and processing techniques. Advanced batteries such as lithium-ion and nickel-metal hydride offer the potential for improved performance if low-cost materials can be developed. This book shares research and highlights the importance of materials in energy conversion technologies. Topics include: rechargeable batteries; lithium-ion rechargeable batteries - modelling; fuel cells; lithium-ion rechargeable batteries - cathode materials; battery electrolytes, interfaces and passive films; lithium-ion rechargeable batteries - anode materials and supercapacitors.