What is a Prismatic Battery
Prismatic battery with busbars being laser weldedA prismatic battery is a battery whose chemical components are enclosed in a rigid casing. Its rectangular shape allows multiple cells to be efficiently stacked in a battery module. There are two types of prismatic batteries: The electrode sheets (anode, separator, cathode) inside the casing are either stacked or rolled and flattened.
For the same volume, stacked prismatic batteries can release more energy at once, thus providing better performance, while flat prismatic batteries contain more energy, thus providing higher durability.
Prismatic batteries are mainly used in energy storage systems and electric vehicles. Their larger size makes them unsuitable for use in small devices such as e-bikes and mobile phones. Therefore, they are more suitable for energy-intensive applications.
Key Differences Between Prismatic and Cylindrical Batteries
Shape is not the only factor that distinguishes prismatic from cylindrical batteries. Other important differences include their size, the number of electrical connections, and their power output.
Size
Prismatic batteries are much larger than cylindrical batteries, so they contain more energy per cell. Roughly speaking, a single prismatic battery can contain the same amount of energy as 20 to 100 cylindrical batteries. The smaller size of cylindrical batteries means they can be used in applications that require less power. Therefore, they have a wider range of applications.
Connections
Because prismatic batteries are larger than cylindrical batteries, fewer cells are needed to achieve the same amount of energy. This means that for the same volume, batteries using prismatic batteries require fewer electrical connections to be welded. This is a big advantage of prismatic batteries because there is less chance of manufacturing defects.
Power
Cylindrical batteries may store less energy than prismatic batteries, but they are more powerful. This means that cylindrical batteries can release energy faster than prismatic batteries. The reason is that they have more connections per ampere hour (Ah). Therefore, cylindrical batteries are ideal for high-performance applications, while prismatic batteries are ideal for optimizing energy efficiency.
Why prismatic batteries may dominate
The electric vehicle industry is growing rapidly, and it is not yet certain whether prismatic or cylindrical batteries will prevail. Currently, cylindrical batteries are more prevalent in the electric vehicle industry, but there is reason to believe that prismatic batteries will become more popular.
First, prismatic batteries offer the opportunity to reduce costs by reducing the number of manufacturing steps. Their form makes it possible to manufacture larger batteries, which reduces the number of electrical connections that need to be cleaned and welded.
Prismatic cells are also ideal for lithium iron phosphate (LFP) chemistry, a cheaper, more readily available blend of materials. Unlike other chemistries, LFP batteries use resources that are available worldwide. They don’t require rare and expensive materials like nickel and cobalt, which drive up the cost of other types of batteries.
