The book discusses the materials, devices, and methodologies that can be used for energy harvesting including advanced materials, devices, and systems. It describes synthesis and fabrication details of energy storage materials. It explains use of high-energy density thin films for future power systems, flexible and biodegradable energy storage devices, fuel cells and supercapacitors, nanogenerators for self-powered systems, and innovative energy harvesting methodologies. This book is aimed at graduate students and researchers in emerging materials, energy engineering, including harvesting and storage.