This book gives a detailed description of the general principles of electrochemical techniques used in supercapacitor characterization and fabrication. Electrical double layer capacitors and pseudocapacitors are discussed, followed by the various electrolyte systems used in supercapacitors. Manufacture of industrial capacitors, testing, and reliability as well as applications of supercapacitors are also covered. Many high performance supercapacitor materials have been developed and new scientific concepts have been introduced. The book provides an authoritative source of information on the synthesis and uses of nanomaterials to enhance the performance of existing electrochemical energy storage systems. The book covers the state of the art of the design, preparation and engineering of nanoscale functional materials as effective catalysts and as electrodes for electrochemical energy storage devices. It also provides perspectives and challenges for future research. The book will be very useful for researchers in academics and the post graduation students to learn the fundamentals of electrochemical techniques and electrochemical capacitors.