ABSTRACT
With the increasing demand for energy and the detrimental effect of fossil fuels on the environment, renewable energy sources are fast emerging as an important alternative to traditional energy sources. Among the alternatives, solar energy holds great potential due to the enormous amount of solar radiation the earth receives. It is estimated that the earth receives about 162,000 TW of solar energy every hour, which is more than 10,000 times the total worldwide energy consumption in 2005. Even if 0.1% of the land area is covered with 10% ef cient solar cells, we can meet our energy demands [1]. In addition to energy conversion, energy storage devices are also gaining increased importance due to the emergence of portable electronic devices and hybrid vehicles. Some popular energy storage devices include lithium ion batteries, electrochemical capacitors, and hydrogen storage materials.
