At present, there are mainly three mainstream Lithium-ion battery types, namely Cylindrical, Prismatic and Pouch. Different battery types mean different characteristics, and they have their own advantages and disadvantages.
Cylindrical Lithium-ion Battery
The earliest Cylindrical Lithium-ion Battery was the 18650 Lithium-ion battery invented by SONY in 1992. Because the 18650 Cylindrical Lithium-ion battery has a long history, the market penetration rate is very high. Cylindrical Lithium-ion batteries use a fairly mature winding process with a high degree of automation, stable product quality and relatively low cost. There are many types of Cylindrical Lithium-ion batteries, such as 14650, 17490, 18650, 21700, 26650 and so on. Cylindrical Lithium-ion batteries are more popular among Lithium-ion battery companies in Japan and South Korea. There are also large-scale enterprises in China that produce cylindrical Lithium-ion batteries.
With the further expansion of the electric vehicle market and the continuous improvement of the requirements for mileage, vehicle companies have put forward higher requirements for power batteries in terms of energy density, manufacturing costs, cycle life and product additional attributes. Under the premise that no major breakthrough has been made in the field of raw materials, appropriately increasing the volume of the Cylindrical Lithium-ion Battery to obtain more battery capacity has become a direction. At present, Tesla has started the large-scale production of 21700 batteries and plans to use them on Tesla Model 3. If it passes the test on other Tesla models, it will replace all the 18650 batteries previously used.