One of the main research areas of the Rettenwander group is the design and development of new materials for energy applications that comprises the synthesis of ceramics (e.g., nanostructures, single crystals, polycrystals, thin films), polymers, and ceramic/polymer composites, their structural and electrochemical characterization as well as their implementation in advanced Li/Na/K/Mg-ion battery technologies. In particular, our group focuses on the key challenges currently hindering the ultimate commercial usage of solid-state batteries, such as Li-metal dendrite formation, and the lack of thermodynamic stability of most solid electrolytes either against Li metal or cathode materials, as well as on the development of contingency strategies to overcome those bottlenecks.