Advantages of the new 21700 lithium battery, the difference between 21700 and 18
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2022/04/27 15:32:35
Advantages of the new 21700 lithium battery, the difference between 21700 and 18650 lithium battery. Like the 18650 battery, the Tesla 21700 lithium battery is a type of cylindrical lithium battery.The 18650 battery was a historical accident. It was the standard of the early products, and now only 21700 lithium batteries can meet the battery performance requirements of electric vehicles.
21700 battery
21700 battery is a diameter of 21mm, height of 70mm lithium battery, because it increases in volume, space utilization ratio, cell and system energy density can be improved, its volume energy density is much higher than 18650 battery, widely used in digital, Electric vehicle, balance vehicle, solar energy lithium battery street lamp, LED lamp, power tools, etc. The battery manufacturers include Tesla, Samsung, Panasonic, Bic and Lion New Energy.
Advantages of the new 21700 lithium battery
1. The capacity of the new 21700 lithium battery is increased by 35%. Taking the 21700 lithium battery produced by Tesla as an example, after the switch from 18650 to 21700, the capacity of a single battery can reach 3-4.8Ah, significantly increased by 35%.
2. The energy density of the new 21700 lithium battery system is increased by about 20%. According to the data disclosed by Tesla, the energy density of the early 18650 lithium battery system is about 250Wh/kg, and the energy density of the later 21700 battery system is about 300Wh/kg. The volume energy density of the 21700 lithium battery is nearly 20% higher than the original 18650.
3. The cost of the system is expected to decrease by about 9%. An analysis of battery pricing information disclosed by Tesla shows that the 21700 battery's power lithium battery system is priced at $170 / Wh, while the 18650 battery system is priced at $185 / Wh. With the use of 21700 lithium batteries in the Model3, battery system costs alone can be reduced by about 9%.
4. The weight of the system is expected to drop by about 10%. The overall volume of the new 21700 lithium battery is larger than that of the 18650 lithium battery. With the increase of the capacity of the single cell, the energy density of the single cell is higher, so the number of cells required under the same energy can be reduced by about 1/3.
5. The energy density of the battery is increased by more than 20%. The energy density of the 21700 battery is better than that of the 18650 battery. According to the current information disclosed by Tesla, the energy density of the 21700 lithium battery system produced by Tesla is around 300Wh/kg under existing conditions, which is about 20% higher than the 250Wh/kg of the original 18650 battery system.
21700 and 18650 lithium battery difference
18650 battery refers to nickel-metal hydride battery and lithium ion battery, because nickel-metal hydride battery is less used now, so now refers to lithium ion battery. Battery 21700 is a cylindrical battery model, specifically refers to: 21 -- refers to the cylindrical battery outer diameter of 21mm; 700 -- the height of the cylindrical battery is 70.0mm. The most obvious difference between 21700 and 18650 lithium batteries is that the size has become larger.
Due to the limitation of battery material performance, increasing the volume to improve the energy density has become the focus of enterprises. China has clearly proposed that the energy density of power battery should exceed 300Wh/kg in 2020, and the energy density of power battery system should reach 260Wh/kg. The energy density of power battery system should reach 350Wh/kg by 2025. The increasing energy density requirement of power lithium battery is bound to continue to boost the change of power lithium battery model.
The energy density of the 21700 battery system is around 300Wh/kg, about 20% higher than the 250Wh/kg of its original 18650 battery system. The increase in battery capacity means that the number of cells required for the same amount of energy is reduced by about a third, which reduces the difficulty of system management and simplifies the number of components such as metal structures. Although the weight and cost of a single cell are increased, the weight and cost of a battery system PACK are reduced.
21700 battery compared with 18650 battery are lithium battery, but the specifications of lithium battery are different, the voltage is the same, but the difference is the size and battery capacity, 21700 must be larger than 18650 size, capacity is also large.
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