Hydrides are compounds containing hydrogen having reducing property. These compounds have wide ranging applications in hydrogen storage, electrochemical, heat storage, other solar related applications and in batteries. This book is a compilation of reviews, research articles on hydrogen material science and application of metal hydrides. Chapters 1-6 deal with the hydrogen economy, modern concepts of energy conversion and storage, effects of structural changes in metal hydrides on hydrogen storage, metal borohydrides and development of hydrogen storage tanks. Electrochemical applications, optical properties and related heat storage materials of solar are discussed in chapters 7-9. Chapters 10-13 focus on additive effects on the properties of metal hydrides and also the effect of hydrogen desorption on cold rolled metal hydrides. Chapters 14-19 highlight the role of metal hydrides in the application of lithium-ion, Nickel/metal hydride batteries. Simulation, prediction of state of health and cell health assessment test is also discussed briefly. These articles give us in-depth details of end-of-life treatment Policy Analysis for Lithium-Ion Batteries and Nickel-Metal hydride batteries. This book is useful to students, chemists and researchers working in the field of batteries and hydrogen storage. The compilation of articles is very broad and up to date. I believe it will enhance the knowledge bank of the personnel pertaining to this subject.