Prismatic vs. Cylindrical Cells: What is the Difference?

Of course, the most apparent difference between a prismatic cell and a cylindrical cell is the shape.

Prismatic Cell

A prismatic cell is thin and rectangular. Because of this, they can easily be made into battery packs holding layers of prismatic cells. The flattened shape holds the energy together and leaves no room for energy to escape. Also, since their shape is flat, prismatic cells can be made into a customizable prismatic battery cell pack for specific applications.

Cylindrical Cells

Cylindrical cells are indeed cylindrical, which can be both an advantage and disadvantage. For example, think of a classic AA battery that goes into your TV remote. These cells are smaller than prismatic tools and can’t be stacked as easily because of their shape. Since the sides are curved, the stacking leaves gaps between the cells instead of compacting them on top of each other.

Although the gaps can be a disadvantage because they take up more space in a battery pack or let out energy, they can also be an advantage to promote airflow, and the cylindrical shape can discharge energy fast without swelling. The shape of cylindrical cells allows them to combat severe environments like space.

Energy density is the amount of energy a cell holds per volume. Depending on the application, the differences in energy density can be a benefit or a hindrance. The topic of energy density is most notable in the EV community as there is debate about what type of energy density an EV should have for optimal safety and longevity.

Whether prismatic vs. cylindrical cells have a greater energy density is also debatable. It is often reported that the cylindrical cell has the higher energy density, but the prismatic cell has more energy per cell due to the larger size and ability to pack closer together.

At the end of the day, it is due to other cell qualities that determine whether prismatic vs cylindrical cells have higher density. With energy and energy density, it’s important to keep in mind the size difference between prismatic and cylindrical and how each is stacked.

Prismatic Cell

A prismatic battery cell has a lifespan of 2,000 cycles. While this is shorter than cylindrical cells, that doesn’t necessarily imply a negative because a long life cycle isn’t always required. A prismatic cell can also reach longer life spans when stacked into a battery pack.

Cylindrical Cell

Cylindrical batteries have a lifespan of 25,000 cycles, which is a driver for their use of longevity.

Thermal performance is how well the cell responds and regulates heat, and the different shapes of the cells are the reason for the difference in their performances.

Cylindrical Cell

Because of the shape, cylindrical cells have a better thermal performance from cycling the energy. Also, the spacing between the cells when stacked keeps the cells from overheating.

Prismatic vs. Cylindrical Cells

Since prismatic cells are stacked on top of each other, they overheat faster and easier than cylindrical cells. The rectangular shape doesn’t cycle the heat as well as the cylindrical shape does. Additionally, since there are no gaps between cells, one overheated prismatic cell can harm the other cells.

Because of their differences in shape, thermal performance, energy density, and lifespan, cylindrical and prismatic cells have different uses. Although they may both be found in certain products, they are generally used for different functions.

Cylindrical Cells

Cylindrical cells are used for electric bikes, medical devices, consumer electronics, smoke alarms, and toys.

Prismatic Cells

Prismatic cells have flexible uses because of the stacking and are commonly used for applications needing high powers. Prismatic cells are used for energy storage systems (ESS), medical devices, hybrid and electric vehicles, and industrial equipment.