The growing use of conventional energy such as fossil fuels results in problems degrading our environment. Hydrogen is frequently discussed as a clean energy in the future without pollution. However, efficient and safe storage of hydrogen constitute a key challenge and unresolved problem. One of the main options is solid-state storage technology. A successful solid-state reversible storage material should meet the requirements of high storage capacity, suitable thermodynamic properties, reversibility and fast adsorption and desorption kinetics. This feature article focuses mainly on the development of thermodynamic improvement of hydrogen storage materials in the past few years including the complex hydride, ammonia borane, and metal-organic frameworks. (C) 2011 Elsevier Ltd. All rights reserved.