What is the difference between Square lithium battery and cylindrical lithium battery?

Square lithium battery and cylindrical lithium battery are both lithium batteries. In addition to their different shapes, what are the differences between the two?

The main difference between the two is actually the safety protection. Compared with the soft pack and the Square lithium battery, the cylindrical lithium battery is the earliest commercialized and the lowest cost lithium battery currently. Square lithium batteries and cylindrical lithium batteries are generally due to differences in structure, material and reaction, and these differences will affect the safety and protection measures of the battery.

The difference between square lithium battery and cylindrical lithium battery in safety protection

At present, the focus of lithium battery protection is generally divided into internal and external parts. The external refers to the threat caused by external forces such as impact and puncture; the internal refers to the threat caused by heat dissipation and attenuation.

But if the two batteries are installed on the vehicle, there is no difference in safety protection. In fact, not only the Square lithium battery and the cylindrical lithium battery, but the soft pack battery is also common in vehicle safety protection. Because the internal composition of the three types of batteries is not much different from square and cylindrical lithium batteries, the biggest difference is that soft pack batteries generally use aluminum-plastic composite film as the shell, while square and cylindrical batteries generally use metal materials as shell.

The protection scheme of Square lithium battery is that when the temperature of the battery rises abnormally, it can present high resistance, thereby hindering the charging and discharging current of the battery to ensure the safe use of the battery.

Cylindrical lithium battery protection scheme is that there is PPTC inside the battery cell for over-temperature and over-current protection, so when the battery cell temperature is too high or the current is too large, the PPTC will become a high resistance state, which will block the battery cell The charging and discharging current prevents the battery from catching fire and explosion, so when using cylindrical lithium batteries, you must also pay attention to temperature, voltage, and current.

In short, whether it is a cylindrical lithium battery or a Square lithium battery, the current rapid development is because they are well used in their respective application fields. Square lithium batteries will become the mainstream of power batteries, but they still need to be technically. With continuous innovation, the energy density of the vehicle battery continues to increase, and the battery performance expression will be more outstanding.