The packaging form of the battery-which cell is more "excellent", such as cylindrical, square, or soft pack?
According to different packaging forms, the battery is divided into cylindrical battery, square battery and soft pack battery. Different structures also mean that they have different characteristics. The following are the advantages and disadvantages of the three structures of batteries.
Cylindrical battery: long development time, most mature technology
The development time of the cylindrical battery is the longest, the technology is also the most mature, and its standardization degree is relatively high. And because the cylindrical battery has a larger space between the individual cells when it is packaged, such batteries have a great advantage in heat dissipation. Many models equipped with cylindrical batteries have adopted lower-cost air-cooling technology.
However, the excessive number of batteries is a tricky problem. Even models with high energy density batteries need to put thousands of cylindrical batteries together, which also puts forward higher requirements for the vehicle battery management system. In addition, because the cylindrical battery needs to use a steel case when assembled into a battery pack, its weight is relatively high. In theory, the energy density of the cylindrical battery is lower than that of the other two batteries.
Square battery: simple structure and light weight
The popularity of square batteries in China is high, because the structure of square batteries is simple, the production process is not complicated, and because square batteries do not use high-strength stainless steel as the casing like cylindrical batteries, the energy density of square batteries is theoretically The energy density is higher than that of cylindrical batteries. However, since square batteries are generally designed for customization, it is difficult to unify the production process of square batteries, and their degree of standardization is low.
Soft battery: high energy density, better flexibility of battery layout
The soft pack battery uses a superimposed manufacturing method, which is thinner in volume compared to the other two types of batteries, so its energy density is theoretically the highest of the three batteries. And because the volume of the soft-pack battery is smaller, its flexibility in battery layout is better than the other two types of batteries.
However, due to the superimposed design inside the soft pack battery, it is necessary to add a thin layer between each two batteries. The thin sheet will be filled with liquid. Heating or cooling will ensure that the battery is at the optimum operating temperature, which also means that the soft pack The battery requires a more complicated battery control system.
In the current new energy vehicle market, three types of batteries, cylindrical, square, and soft packs, are equipped with models. There is no absolute good or bad, only that they have their own advantages. In terms of cell energy density, in theory, the soft battery is the highest, the square battery is second, and the cylindrical battery is the smallest.