Cylindrical lithium-ion batteries have 18650 batteries and 21700 lithium battery has become the most common lithium battery cells. And apply widely in different industry area.
With the rapid development of new energy vehicles in recent years, lithium batteries are also developed quickly. Lithium ion battery has always been an important field for new energy vehicles. Which kind of battery will be a major energy for vehicles?
Lithium-ion batteries have a high energy density, and has a very low self-discharge rate. In addition, lithium-ion batteries with no “memory effect” and no toxic substances, and these advantages of lithium-ion batteries make them widely used in new energy vehicles.
21700 battery is a cylindrical battery model, specifically refers to: 21 – refers to the cylindrical battery has an outer diameter of 21mm; With height: 70mm.
This is to adapt to the electric vehicle’s longer-lasting mileage requirements, in order to improve the effective utilization of vehicle battery space, and developed a new model. The same material, 21700 compared to the common 18650 cylindrical lithium battery, capacity can be more than 35% higher.

Advantages of 21700 battery cell compared with 18650

- 21700 battery cell capacity increased by 35%. Take tesla 21700 battery as an example, and When Tesla switch from the 18650 to the 21700 model, the battery capacity can reach 3 to 4. 8Ah, a significant increase of 35%.
- The energy density of the battery system is increased by about 20%. According to data disclosed by Tesla, the energy density of the 18650 battery system used in the early days was about 250Wh/kg, and later its 21700 battery system energy density was about 300Wh/kg, and the volume of the 21700 battery had a nearly 20% higher energy density than the original 18650 cell.
- The cost of the system is expected to fall by about 9%. According to a analysis of the battery price information disclosed by Tesla, the 21700 battery powered lithium battery system costs $170/Wh, while the 18650 battery system sells for $185/Wh. With the 21700 battery on the Model3, battery system costs alone can be reduced by about 9%.
- The weight of the system is expected to decrease by about 10%. The overall volume of 21700 is greater than 18650, with the increase of monomer capacity, the single body energy density is higher, so the number of battery monomers required under the same energy can be reduced by about 1/3, in reducing the difficulty of system management will also reduce the number of metal structure parts and electrical accessories used in the battery pack, which further reduces the weight of the battery. After samsung’s SDI switched to a new 21700 battery, it was found that the system was 10% lighter than the current battery.
Keep the advantages like high reliability and stable performance of the 18650 battery, the 21700 battery performance is much more improved over the 18650 in all aspects. In addition, compared to other battery models, lithium 21700 is similar to the more mature 18650 battery in terms of battery raw material selection, production process and technical processes. Therefore, the 18650 and 21700 production line can be mostly compatible, some enterprises more secure way is to do articles on the production line, the production line to 21700 and 18650 compatible close.
The pursuit of high-ratio energy has become an trends, many battery companies began to turn their attention to the layout of 21700 batteries. Some enterprises’ production lines are imported by introduce more equipments, but they are assembled on their own, so they can invest less in the cost of 18650 to 21700 conversion.
At present, The most popular model like Sanyo 21700, Sony 21700 battery vtc6a, Nitecore 21700, Panasonic 21700 battery, LG 21700, Inr21700 M50. They are already for sale. And Coremax also get ready for 21700 battery packs.

panasonic 21700 battery

LG 21700 battery
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Cell Capacity: 5000 mAh
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Max Continuous Discharge: 7.3A
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Cell Weight: 68 g
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Datasheet Download

sony 21700
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