With the rapid development of the global economy, the depletion of fossil fuels and increasing environmental pollution, there is an urgent need for efficient, clean, and sustainable sources of energy, as well as new technologies associated with energy conversion and storage. Electrical energy storage devices are mandatory in myriad applications viz., telecommunication devices (cell phones, remote communication, walkie-talkies etc), lightweight electronic fuses, backup power sources for calculators and digital calipers, surge-power delivery devices and electric hybrid vehicles in the form of storage components. These prompted the need for advanced power sources offering high power density. ?Supercapacitors? introducing new energy storage device which can instantaneously provide a higher power density than batteries and higher energy density than conventional capacitors. It is with the above-astounded advantages and applications in mind, the book is embarked at developing supercapacitors using nanostructured and inexpensive metal oxides as potential electrodes focusing on high power supercapacitors in general and pulse power applications in particular.