Electrical engineering

Physics

Electrode

Organic chemistry

Engineering physics

Energy storage

Endocrinology

Engineering

Intercalation (chemistry)

Nanoarchitectures for lithium-ion batteries

Physical chemistry

Organic radical battery

Power (physics)

Inorganic chemistry

Chemistry

Renewable energy

Metallurgy

Materials science

Lithium (medication)

Sodium

Battery (electricity)

Electrolyte

Energy density

Electrochemistry

Medicine

Thermodynamics

Advanced Energy Materials

This paper gives an overview of the research carried out on sodium batteries in the last 50 years. The discovery of the very high Na + ion conductivity in β‐Al 2 O 3 opened the way to high‐energy batteries (sodium/sulfur and sodium/NiCl 2 ) for load leveling and electrical vehicles. Then, the liquid electrolyte batteries were considered with intercalation‐based electrodes and lithium and sodium as mobile ions. When Sony proposed the lithium‐ion batteries, most research moved to lithium systems, exhibiting a higher energy density. These are now currently used in electronic devices, hybrid electrical vehicle (HEV) and electrical vehicle (EV). The development of renewable energies, which have an intermittent character, requires very large batteries for frequency regulation and peak production shift. For these stationary applications the most important parameters are the lifetime, the power, the price, and the material availability. Since sodium ion batteries are able to satisfy these criteria, these new material families now concern a large part of the scientific community. This article gives a general introduction and an overview of the research carried out on the materials that are presented in detail, in the articles within this special issue on sodium batteries.

Sodium and Sodium‐Ion Batteries: 50 Years of Research