What types of lithium-ion cells are there?

The pouch or polymer cell has no metal housing. Instead it is surrounded by an aluminised plastic film. This cell is usuallyused in model constructions.

Advantage:

• High performance
• Flat design
• Very light

Disadvantage:

• There is no industrial standard for the shape, and therefore no second source
• Production is less automated, which results in large production tolerances
• Less shape stability over service life and therefore difficult to process in terms of design
• Susceptible to impacts and scratching

The prismatic cell is located in a solid cell cup and has an especially thin cell shape. No polymer is used here – instead, it is liquid electrolyte. Standard sizes are actually available for this cell type. However, they can only be procured from a handful of manufacturers.

Advantage:

• Flat design

Disadvantage:

• Moderate capacities
• Less shape stability over service life and therefore difficult to process in terms of design

The 18650 round cell is a cell in cylindrical form. Here the liquid electrolyte is located in a solid cell cup.

Advantage:

• Highly automated production with the lowest production tolerances
• Available from all notable cell manufacturers
• Form stability due to cylindrical design shape and, thus, easy to process in terms of design
• Contains additional protective mechanisms in the cell structure

Disadvantage:

• Not suitable for flat devices; e.g. mobile phones

This cell type boasts exactly the same features as the 18650 round cell, but it is smaller and less widely distributed.