After an introduction to Na-ion batteries and their comparison with Li-ion batteries, the book provides an in-depth coverage of the development and performance of cathode and anode materials and their characterization by methods such as NMR spectroscopy and magnetic-resonance imaging. Solid and liquid electrolytes such as ceramics and ionic liquids are subsequently discussed in detail. Furthermore, the book gives an overview of commercial perspectives, upscaling, cost analysis, and safety issues of Na-ion batteries.