The so-called “energy crisis”, that concerns the global economy as a consequence of the increasing energy demand, the limited natural conventional resources and political and environmental reasons, has led to the need of developing new energy sources. The most developed countries are economically supporting both basic and applied research focused on technology of new sources of energy. In this context, synthesis, structural characterization and study of the electrical and electrochemical properties of new materials are essential areas of Materials Science for optimizing energy-supply or energy-storage devices. This symposium provides an overview of current research on new inorganic materials for power supply or storage of energy, mainly in the fields of Li and post-Li rechargeable batteries and Fuel Cells.