A sodium ion cell, commonly known as a sodium-ion battery, is an energy storage device that uses sodium ions to facilitate the flow of electrical current. Similar to lithium-ion batteries, sodium-ion cells consist of an anode, cathode, and an electrolyte, but they use sodium ions instead of lithium ions for energy storage.

The anode of a sodium-ion cell is typically made of materials such as hard carbon or porous metal oxides, which can effectively intercalate sodium ions during charging. Meanwhile, the cathode is often composed of sodium metal oxides or polyanion compounds, which can reversibly store and release sodium ions.

Sodium-ion batteries are advantageous due to the abundance and low cost of sodium compared to lithium. These batteries are suitable for stationary energy storage applications, such as renewable energy integration and grid stabilization. However, their energy density and cycle life are currently lower than those of lithium-ion batteries, making them less suitable for portable electronic devices.

Research and development efforts are ongoing to improve the performance and longevity of sodium-ion cells, with the aim of making them a competitive alternative to lithium-ion batteries in various applications.