Combining high energy density and high power delivery, supercapacitors are an attractive form of energy storage compared to batteries and dielectric capacitors.Their rapid charge/discharge cycles and superior longevity are of particular interest to many industries, including transport, telecommunications, defence, and energy distribution. The introductory chapters to this book present the fundamentals of this growing technology, including design principles and fabrication of supercapacitors, through to manufacture at an industrial scale.With electrode materials key to their design, much of the second part of the book explores the range of their sources, including biomass feedstocks and composites.Combining this knowledge, the third part of the book is dedicated to various applications around the world, supported by case studies and opportunities for commercialisation and sustainability.