Study of Carbon Materials and Effect of its Ball Milling, on Capacitance of Supercapacitor

Abstract

The various forms of energy are available in nature, however the electrical energy is the most convenient form of energy for any application. Due to this reason, day by day the demand of electrical energy is rapidly growing in this decade. There is always mismatch in time zone between availability of energy especially from renewable energy sources and demand. Thus, the storage of electrical energy is now becoming important. However, amount of electrical energy which can be stored is again a critical issue in many renewable energy systems. Supercapacitor can be a new technology for the storage of electrical energy. Supercapacitors are currently a prominent area of research for energy storage devices as they have high power density, long cycling time, and short charging time. Due to a short charging time feature of supercapacitor, in future it can have application in hybrid cars. Supercapacitor is similar to a regular capacitor in operation, however it offers a very high capacitance in a small package for achieving the requirement of power supplies. Capacitance, internal resistance, self discharge, ageing, pulse current, size, shape are some of the parameters in selection of supercapacitor in various applications. Capacitance value of capacitor is very important in energy storage system as amount of energy stored by capacitor is directly proportional to its capacitance value. The capacitance value of supercapacitor depends on types of carbon material and method of construction of supercapacitor. Various kinds of activated carbon materials are available with different pore size, pore density and specific surface area, are found more suitable to get higher values of capacitor. In this research work, the properties of various carbons are studied to select appropriate carbon material to construct the supercapacitor. Supercapacitor along with fuel cell can address many issues related to effective electrical energy storage and it can have number of applications in future. This research work also presents the effect of ball milling of an electrode material on the value of capacitance of an aqueous metal oxide based supercapacitor.