The increasing demand for energy storage devices has prompted researchers to develop cost-effective materials with enhanced performance. Nanostructured materials play an important role for the fabrication of high-performance energy storage devices. This book focuses on the importance of nanostructures, mechanism of energy storage, electrode-electrolyte interface, defects and hybrid materials for the fabrication of enhanced energy storage devices such as supercapacitor and batteries. The book looks at the current scenario, challenges and future scope of enhanced energy storage devices