The first thing we want to talk about is the most popular cylindrical battery currently. As early as 1992, Japanese company SONY developed 18650 batteries. The current cylindrical batteries can be divided into models such as 14650, 18650, 21700, etc., which are named after the battery size. I believe everyone has heard of 18650 and 21700 batteries. 18650 is currently the most common battery model on the market and the most mature technology, while 21700 is a new type of battery that Tesla has been promoting in recent years. The size of a single cylindrical battery has become larger and the battery capacity has also increased. In this way, the number of battery cells can be significantly reduced, making the vehicle more proficient in controlling the battery system.

Let's talk about the advantages of cylindrical batteries first. Firstly, after years of development, the standardization level of cylindrical batteries is relatively high, making it easy to achieve unified standards within the industry. In addition, cylindrical batteries also have inherent advantages in heat dissipation. When packaging, there is a good heat dissipation space between the cylinders, so some vehicles equipped with cylindrical batteries use low-cost air cooling technology.

Of course, cylindrical batteries also have disadvantages. For vehicles using cylindrical batteries, it is inevitable to face battery control issues caused by a large number of individual batteries. After all, even with 21700 batteries, thousands of cylindrical batteries need to be placed together to form a battery pack, which is very large. In addition, due to the use of steel shells when combining cylindrical batteries into battery packs, their weight is relatively high and their energy density is insufficient compared to the other two shapes of batteries.

In terms of battery shape, most cylindrical battery packs can only be arranged in a rectangular layout and installed below the vehicle, which is relatively simple because it can ensure that the battery pack does not affect the front and rear weight of the entire vehicle, but it will have an impact on the ground clearance of the vehicle and the height of the platform inside the carriage. Some hybrid models that choose to place the battery pack under the trunk, although achieving a balance in weight distribution, also sacrifice the trunk space.

Next, let's talk about square batteries. Square batteries have stronger plasticity and can be customized according to the specific needs of the products they carry. This also leads to varying sizes, and currently there is no clear standard division as cylindrical batteries, regardless of manufacturing process or application standards. But precisely because of its high flexibility, it has been used for a long time in early new energy vehicles, and car companies can customize the size of square batteries according to the needs of the vehicle model. Square batteries were once considered the most suitable battery design for new energy vehicle applications. In fact, there are many square battery packs on the market, although they are nominally square batteries, the internal essence will still be discussed later

The flexible battery is thinner and has the highest energy density because of the superposition manufacturing method, which is also in line with the development trend of the Alternative fuel vehicle market in China. In addition, the soft pack battery can also be customized according to different needs. Because the controllability of its volume is also valued by car brands, especially for hybrid models, when considering both the overall layout and weight of the vehicle,