What Are Cylindrical Cells?

A cylindrical cell is a cell enclosed in a rigid cylinder can. Cylindrical cells are small and round, making it possible to stack them in devices of all sizes. Unlike other battery formats, their shape prevents swelling, an undesired phenomenon in batteries where gasses accumulate in the casing.

Cylindrical cells were first used in laptops, which contained between three and nine cells. They then gained in popularity when Tesla used them in its first electric vehicles (the Roadster and the Model S), which contained between 6,000 and 9,000 cells.

Cylindrical cells are also used in e-bikes, medical devices, and satellites. They are also essential in space exploration because of their shape; other cell formats would be deformed by the atmospheric pressure. The last Rover sent on Mars, for example, operates using cylindrical cells. The Formula E high-performance electric race cars use the exact same cells as the rover in their battery.