A, cylindrical lithium battery cells

1、Cylindrical lithium-ion battery cell brand

Cylindrical lithium battery is more popular in Japan, South Korea lithium battery companies, China also has a sizeable domestic enterprises to produce cylindrical lithium battery. The earliest cylindrical lithium battery was invented by Japan SONY in 1992.

Well-known cylindrical lithium-ion cell brands: Sony, Panasonic, Sanyo, Samsung, LG, Wanxiang A123, BAK, Lixin, etc.

2、Types of cylindrical lithium-ion battery cells

Cylindrical lithium-ion cells are usually indicated by five digits, counting from the left, the first and second digits refer to the cell diameter, the third and fourth digits refer to the cell height, and the fifth digit indicates the round shape. There are many models of cylindrical lithium batteries, the more common ones are 10400, 14500, 16340, 18650, 21700, 26650, 32650, etc.

①10440 battery

10440 battery is a kind of lithium battery with a diameter of 10mm and a height of 44mm, which is the same size as what we often call "No. 7 battery", and the capacity of this battery is generally very small, only a few hundred mAh, mainly used in mini electronic products. For example, flashlights, mini stereos, amplifiers, etc.

②14500 battery

14500 battery is a kind of lithium battery with a diameter of 14mm and a height of 50mm, this kind of battery is generally 3.7V or 3.2V, the nominal capacity is relatively small, a little larger than 10440 battery, generally 1600mAh, the discharge performance is superior, the application area is mainly in consumer electronics, such as wireless audio, electric toys, digital cameras, etc.

③16340 battery

16340 battery is a kind of lithium battery with a diameter of 16mm and a height of 34mm. This kind of battery is often found in strong flashlights, LED flashlights, headlamps, laser lights, lighting fixtures, etc. because the height of the ruler is a little shorter and the capacity is not very small.

④18650 battery

18650 battery is a kind of lithium battery with a diameter of 18mm and a height of 65mm, its biggest feature is that it has a very high energy density, almost 170 watt hours / kg, so this battery is a better cost performance, we usually often see most of this battery, because it is more mature lithium battery, all aspects of the system quality stability is better, widely used in 10 kWh About the battery capacity occasions, such as in, in cell phones, laptops and other small appliances.

⑤ 21700 battery

21700 battery is a kind of lithium battery with a diameter of 21mm and a height of 70mm, because its volume increases, the space utilization becomes larger, the energy density of the cell monomer and the system can be improved, its volume energy density is much higher than 18650 type batteries, widely used in digital, electric vehicles, balance cars, solar energy lithium battery street lights, LED lights, power tools, etc.

⑥ 26650 Battery

26650 battery is a 26mm diameter, 65mm height lithium battery, nominal voltage 3.2V, nominal capacity 3200mAh, this battery with excellent capacity and high consistency and other characteristics, has gradually become a trend to replace the 18650 battery, many products in the power battery will also gradually favor this.

(7) 32650 battery

32650 battery is a 32mm diameter, 65mm height lithium battery, this battery has a strong capacity for continuous discharge, so it is more suitable for electric toys, backup power, ups battery, wind power generation system, wind and wind complementary power generation system.

Second, the cylindrical lithium battery market development

Cylindrical lithium-ion battery technology progress mainly from the key battery materials innovation research and application progress, through the development of new materials to further improve battery performance, improve quality, reduce costs and improve safety. In order to meet the requirements of downstream applications for battery specific energy enhancement, on the one hand, through the use of high specific capacity materials, on the other hand, by increasing the charging voltage, the use of high voltage materials.

Cylindrical lithium-ion battery from 14500 development to Tesla 21700 battery, in the recent mid-term development, in the optimization of the existing system of lithium-ion power battery technology to meet the needs of the scale development of new energy vehicles, while focusing on the development of new lithium-ion power battery to improve its safety, consistency and life and other key technologies, synchronize the forward-looking research and development of new system power battery.

For the medium and long-term development of cylindrical lithium-ion batteries, while continuing to optimize and enhance the new lithium-ion power battery, focus on the development of new system power battery, significantly improve the specific energy, significantly reduce costs, and achieve the practical and large-scale application of the new system power battery.

Third, cylindrical lithium batteries and square lithium battery comparison

1. Battery shape: square size can be designed arbitrarily, while the cylindrical battery can not be compared.

2. Multiplier characteristics: cylindrical batteries welding multi-pole lug process limitations, multiplier characteristics are slightly worse than the square multi-pole lug battery.

3. Discharge platform: Theoretically speaking, the discharge platform of lithium batteries with the same positive and negative electrode materials and electrolyte should be the same, but the discharge platform of square lithium batteries is slightly higher.

4. Product quality: The manufacturing process of cylindrical batteries is more mature, and there is a low chance of secondary slitting defects in the pole piece, and the maturity and automation of the winding process are relatively high, and the iteration process is still semi-manual, which has a negative impact on the quality of the battery.

5. Lug welding: cylindrical battery lugs are easier to weld than square lithium batteries; square lithium batteries are prone to false welding, which affects the quality of the battery.

6. PACK into groups: cylindrical batteries have easier to use features, so PACK technology is simple and heat dissipation is good; square lithium batteries PACK to solve the problem of heat dissipation.

7. Structural characteristics: square lithium batteries are less chemically active at the corners, long-term use of battery energy density is easy to decay, the range is shorter.

Fourth, cylindrical lithium batteries and soft pack lithium battery comparison

1. Soft pack battery safety performance is better, soft pack battery in the structure of the aluminum-plastic film packaging, the occurrence of safety problems, soft pack battery will generally bulge crack, unlike the steel or aluminum-cased battery cell explosion; in the safety performance is better than the cylindrical lithium battery.

2. Soft pack battery weight is relatively light, soft pack battery weight is 40% lighter than the same capacity of steel-case lithium battery, 20% lighter than the cylindrical aluminum-case lithium battery; internal resistance is small, the internal resistance of soft pack battery is smaller than lithium battery, which can greatly reduce the self-consumption of battery power;

3. Soft pack battery cycle performance is good, the cycle life of soft pack battery is longer, 100 times less than cylindrical aluminum shell battery cycle decay 4% to 7%;

4. Soft pack battery design is more flexible, the shape can be any shape, can be thinner, can be customized according to customer needs, the development of new cell models. And cylindrical lithium batteries do not have this condition.

5. Compared with cylindrical lithium batteries, the shortcomings of soft pack batteries are poor consistency, higher cost and easy to leak. The high cost can be solved by large-scale production, and the leakage can be solved by improving the quality of aluminum plastic film.

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