With the social progress and the growth in human lifestyle, the need for energy increases continuously. Energy is considered as the most important problem facing humanity. Successful exploitation of renewable but intermittent energy sources such as wind and solar power requires reliable and efficient electrical energy storage and scientific community is studying new energy storage devices, electrochemical energy storage devices being the most promising candidates. Electrochemical energy storage technologies include batteries, fuel cells and electrochemical capacitors. Based on charge storage mechanisms, capacitors can be divided into two groups: electric double layer capacitors (EDLCs) and pseudo-capacitors (also known as redox and faradaic supercapacitors). Supercapacitors, with many superior characteristics, can partly or completely replace the traditional chemical batteries, especially in high power applications. So most of the developed countries are sparing no effort to research and develop supercapacitors.