This course covers energy storage technologies from the perspective of material scientists. It provides an overview of the energy storage field, including electrochemical, chemical, thermal, and  mechanical storage, with emphasis materials innovations required to meet the performance metrics for various applications. Relevant fundamental concepts of material science and electrochemistry are first discussed. The Li-ion battery system is then studied in detail, including anodes, cathodes, electrolytes, separators, charge storage mechanisms, performance metrics, and testing protocols. This is followed by discussing other battery technologies, including mobile ion batteries, metal anode batteries, aqueous batteries, metal-air, metal-sulfur, and redox flow batteries. Electrochemical capacitors are then studied, covering their design, electrode materials, charge storage mechanisms, and emerging applications. In the latter part of the course, chemical storage (e.g., H2 storage) and thermal storage technologies are studied.