18650 battery or 21700 battery who is better

The 21700 battery is the model of the cylindrical battery, 21 in detail refers to the cylindrical battery with an outer diameter of 21mm; 700 refers to the cylindrical battery with a height of 70.0mm. Both the 18650 battery and the 21700 battery are batteries developed to meet the requirements of electric vehicles for longer mileage and to improve the effective utilization of vehicle battery space, but the battery sizes are different. Therefore, compared with the common 18650 cylindrical lithium battery under the same material, the capacity of 21700 can be more than 35% higher. The new 21700 has four significant advantages: (1) The battery cell capacity is increased by 35%. Taking the 21700 battery processed by Tesla as an example, after switching from the 18650 model to the 21700 model, the battery cell capacity can reach 3 to 4.8 Ah, a significant increase of 35%. (2) The energy density of the battery system is increased by about 20%. According to the data disclosed by Tesla, the energy density of the 18650 battery system used in the early days was about 250Wh/kg. Later, the energy density of the 21700 battery system processed by it was about 300Wh/kg. The volumetric energy density of the 21700 battery was higher than the original 18650. Nearly 20%. (3) The cost of the system is expected to drop by about 9%. Decomposing from the battery price information disclosed by Tesla, the power lithium battery system of the 21700 battery is priced at US$170/Wh, and the price of the 18650 battery system is US$185/Wh. After using 21700 batteries on Model 3, the cost of the battery system alone can be reduced by about 9%. (4) The weight of the system is expected to drop by about 10%. The overall volume of 21700 is greater than 18650. As the monomer capacity increases, the energy density of the monomer is higher, so the number of battery monomers required under the same energy can be reduced by about 1/3, which will reduce the difficulty of system management and reduce the number of batteries. The number of metal structural parts and electrical accessories used in the group further reduces the weight of the battery. After Samsung SDI switched to a new set of 21700 batteries, it was found that the weight of the system was reduced by 10% compared to current batteries. (5) Maintaining the high reliability and stable performance of the 18650 battery, the performance of the 21700 battery is greatly improved compared to the 18650 in all aspects. In addition, compared to other battery models, the 21700 is similar to the more mature 18650 battery in terms of battery raw material selection, production process and technical process. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous post: Comparison of 18650 lithium battery and polymer lithium battery