Supercapacitors as next generation energy storage devices: properties and applications

Supercapacitors are considered comparatively new generation of electrochemical energy storage devices where their operating principle and charge storage mechanism is more closely associated with those of rechargeable batteries than electrostatic capacitors. These devices can be used as devices of choice for future electrical energy storage needs due to their outstanding performance characteristics. Based on their performance, supercapacitors can be placed somewhat in middle of rechargeable batteries and conventional electrostatic capacitors since supercapacitors have higher energy and power densities when compared with electrostatic capacitors and rechargeable batteries respectively. Supercapacitors have seen increased use recently as stand-alone as well as complementary devices along with other energy storage systems such as electrochemical batteries. Therefore, it is believed that supercapacitors can be a potential alternative electrochemical energy storage technology to that of widely commercialized rechargeable batteries especially lithium-ion batteries. In this brief prospective, authors have attempted to present an overview of the evolution of supercapacitor technology and its current/future applications.