What are the main forms of lithium batteries?

Lithium batteries are mainly divided into two types according to the different packaging forms, metal shell packaging and soft package packaging. The difference between the two is that in addition to the different shell materials, the packaging method is also different. The soft package core uses aluminum plastic packaging film as the packaging material, mainly using thermal packaging, while the metal shell core generally uses steel or aluminum shells, using welding(laser welding) as the packaging method.

Metal shell packaging mainly includes two types of circular lithium batteries and square lithium batteries. Circular lithium batteries can be divided into 18650 and 21700 mainstream models depending on the specific model.

18650 battery: 18650 is the originator of lithium-ion batteries-a standard lithium ion battery model set by SONY of Japan in order to save costs, of which 18 represents a diameter of 18mm, 65 represents a length of 65mm, and 0 represents a cylindrical battery.

21700 Battery: Developed jointly for Tesla and Panasonic, 21 means 21mm in diameter, 70 means 70mm in length, and 0 means cylindrical battery.

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