This book explores the fundamental properties of a wide range of energy storage and conversion materials, covering mainstream theoretical and experimental studies and their applications in green energy.It presents a thorough investigation of diverse physical, chemical, and material properties of rechargeable batteries, supercapacitors, solar cells, and fuel cells, covering the development of theoretical simulations, machine learning, high-resolution experimental measurements, and excellent device performance. • Covers potential energy storage (rechargeable batteries and supercapacitors) and energy conversion (solar cells and fuel cells) materials. • Develops theoretical predictions and experimental observations under a unified quasi-particle framework. • Illustrate up-to-date calculation results and experimental measurements. • Describes successful synthesis, fabrication, and measurements, as well as potential applications and near future challenges. Promoting a deep understanding of the basic science, application engineering, and commercial products, this work is appropriate for senior graduate students and researchers in materials, chemical, and energy engineering and related disciplines.