Cylindrical battery: long development time, the most mature technology
Cylindrical batteries have the longest development time, and the technology is the most mature, with a high degree of standardization. Moreover, because the cylindrical battery has a large space between the batteries when it is packaged, such a battery has great advantages in heat dissipation.
However, the excessive number of batteries is a relatively difficult problem. Even if a vehicle with a high energy density battery, thousands of cylindrical batteries need to be put together, which puts higher requirements on the vehicle battery management system. In addition, since the cylindrical battery needs to adopt a steel shell when assembled into a battery pack, its weight is relatively high. Theoretically, the energy density of the cylindrical battery is lower than that of the other two batteries.
At present, this types of batteries are used in many models of cars, and the representative one is Tesla's model 3, which uses the model number 21700 (21 means the diameter of the cylindrical battery is 21mm, 70 means the battery length is 70mm, 0 indicates a cylindrical battery)
Square battery: simple structure and light weight
The popularity rate of square batteries in China is very high, because the structure of square batteries is relatively simple, the production process is not complicated, and because square batteries do not use high-strength stainless steel like cylindrical batteries, the energy density of square batteries has a higher energy density than a cylindrical battery. However, since the prismatic batteries are generally custom-designed.
Soft Pack Battery: High Energy Density, Better Flexibility of Battery Layout
The soft pack battery adopts a superimposed manufacturing method, and is slimmer than the other two types of batteries, so its energy density is the highest among the three types of batteries. And because the soft pack battery is smaller, it is better than the other two types of battery in the flexibility of the battery layout.