What are the advantages of cylindrical lithium batteries? What is its structure?

Cylindrical lithium batteries have many advantages: First, it has a large energy density and a high average output voltage. Moreover, its self-discharge is small. Everyone should know that a good battery is very durable. Because the cylindrical lithium battery has no memory effect, it is very durable and has a long service life. In addition, cylindrical batteries also have many advantages such as superior cycle performance, fast charging and discharging, high charging efficiency, and large output power. It is worth mentioning that cylindrical lithium batteries do not contain toxic and hazardous substances and are called green batteries, so everyone can use them with confidence. Compared with soft packs and square lithium batteries, the 18650 cylindrical lithium battery is the earliest commercialization, the highest degree of processing automation, and the current lowest cost power lithium-ion battery. Tesla has been holding it for many years, and it basically maintains a three-thirds position with soft packs and square batteries. Since Tesla announced the use of 21700 Model 3, the cylindrical battery family has also added a star member. This article will take a look at several technical points related to cylindrical batteries. If there is no special statement below, the cylindrical battery refers specifically to 18650. Cylindrical battery structure If you pay attention to the power lithium-ion battery, you will find that the cylindrical 18560 battery is the most studied and technically discussed battery type. The monomer is mainly composed of a positive electrode, a negative electrode, a diaphragm, a positive and negative electrode collector, a safety valve, an overcurrent protection device, an insulator and a shell. For the shell, there were many early steel shells, but currently aluminum shells are the main ones. The design of the monomer overcurrent protection device is different from each manufacturer. According to the different safety requirements, the price will be different and can be customized. General safety devices mainly include PTC positive temperature coefficient resistors and fuse devices. PTC, when there is excessive current, resistance heating, temperature accumulation will promote the increase of PTC resistance. When the temperature exceeds a threshold, it will increase suddenly, which is equivalent to isolating the faulty cell from the overall circuit to prevent further thermal runaway happened. The fuse device, in principle, is a fuse. When encountering excessive current, the fuse is blown and the circuit is disconnected. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.