ABSTRACT
Portable energy storage devices have had a profound impact on the development of automobiles and electronics which influences all aspects of day-to-day life. The most convenient form of energy storage is portable chemical energy such as batteries and supercapacitors. Among the different sources, fossil fuel has become the dominant chemical energy source due to its ease of storage, access, and transport. However, there are serious environmental issues associated with the use of fossil fuels. It is a well-known fact that carbon dioxide, which is the gas released when fossil fuels are burned, is one of the primary gases responsible for global warming. Such gases cause a rise in the earth’s temperature to the point that polar ice caps are melting, low-lying lands are flooding, and sea levels are increasing which threatens the existence of many animals and plants including mankind. Fossil fuels are a non-renew-able energy source and are being extracted at an exorbitant rate to meet demand. It is estimated that fossil fuels will be extinct within the next 30-40 years, hence a steep hike in fuel costs is expected in the near future. In this scenario, if an effective alternate to oil is not found or automobiles do not switch from gasoline engines to electrically powered engines, we will no longer be able to drive cars. To make such a switch, it is necessary to have better energy conversion and storage devices. Among the different energy storage devices, rechargeable batteries are the most promising as they are capable of efficiently storing energy from renewable sources. On a fundamental level, the battery cell is composed of three integral components: the anode, the cathode, and the electrolyte/ionic conductor. The major components and structure of a battery are shown in Figure 2.1.
