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 Illustrates 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 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.