The portable storage and generation of electrical energy is a significant and limiting technological problem in the world. Portable electronic devices have dramatically improved the quality of life in the modern world. The growth of wireless communication in these devices has almost eliminated the need to be connected, if it were not for limitations of power. Lack of long life batteries limits the capabilities of these technologies and reduces consumer satisfaction in using them. In some cases, this power limitation is so severe that it can cripple new technology. When G3 GSM phones were introduced in Europe, consumers refused to adopt the new technology because of short battery life. The recent development of hybrid electric vehicles (HEVs) has posed another great challenge to the research of portable energy sources. In a HEV, the fuel savings is directly related to the size and weight of the battery that can be installed as larger batteries allow the recoup of more energy from regenerative braking and increase the time that the engine can be turned off. Batteries and fuel cells are considered as efficient, clean and portable energy sources; however, new materials have yet to be designed to achieve higher energy/power densities, longer cycle lives and better reliability in order to meet the ever-increasing energy demands.