ABSTRACT
The breathtaking technological innovations in all walks of life continue to make human life on earth more and more comfortable day by day. However, the reality that the existing energy resources fueling these technologies are being exhausted at an alarmingly faster pace should not be overlooked. The biggest challenge before human society in the present century is to develop and maintain sustainable and green energy resources to support comfortable human life for many, many future generations. Practical realization of renewable and efcient energy sources is the urgent need of the hour. When it comes to energy generation, the signicance of energy storage follows naturally.
