22 Years' Battery Customization
Dec 05, 2019 Pageview：2683
IEC international standard
Common in the battery industry is an IEC international standard. The IEC (International Electrotechnical Commission) has established the IEC battery standard to promote standardization in the world of electrical and electronic fields. IEC61960 is a standard for the specification of electrical performance parameters (capacity, circulation, internal resistance, etc.) of lithium battery cells and battery products.
According to the IEC61960 standard, the lithium battery cell type identification is mainly composed of the following parts:
The first part (3 letters):
The first letter indicates the negative electrode material of the battery. “I” denotes a lithium ion having a built-in battery, and L denotes a lithium metal electrode or a lithium alloy electrode.
The second letter indicates the positive active material of the positive electrode of the battery. C denotes a cobalt-based electrode, N denotes a nickel-based electrode, M denotes a manganese-based electrode, V denotes a vanadium-based electrode, and T denotes a titanium-based electrode.
The third letter indicates the shape of the battery. R denotes a cylindrical battery, and L denotes a square battery.
The second part (5/6 digits):
The cylindrical battery letter followed by 5 digits represents the battery size specification, the first two digits represent the circular diameter (mm), the middle two digits represent the battery height (mm) * 10, and the last digit has no meaning of 0. When any of the above specifications >= 100mm, add "/" between the two numbers. Common models are 14500, 14650, 17490, 18500, 18650 and 26500.
Common cylindrical battery specifications: 186502200mAh3.7V, Sanyo 186502500mAh3.7V.
The square battery letter is followed by a 6-digit number, which also represents the battery size specification. The first two digits represent the battery thickness (mm), the middle two digits are the battery width (mm), and the last two digits are the battery height (mm). When any of the above specifications >= 100mm, add "/" between the two numbers; when any of the above specifications <1mm, add the letter "t" before the size and enlarge the unit by 10 times. Common BAK, Sanyo square battery specifications: BAK 063450A1200mAh3.7V, Sanyo UF103450P1880mAh3.7V.
The square battery can be added with a letter at the end of the specification to indicate the battery material, S for the steel shell and A for the aluminum shell.
Finally, a new digit can be added to indicate the number of battery cells connected in parallel. If it is 1, it will not be displayed.
ICR18650 model: cylindrical lithium-ion battery, the main material of the positive electrode is cobalt, diameter 18mm, height 65mm
ICR20/1050 model means: cylindrical lithium ion battery, cathode material is cobalt, diameter 20mm, height 105mm
ICP063048S model represents: square secondary lithium-ion battery, the main material of the positive electrode is cobalt, the thickness is 6 mm, the width is 30 mm, the height is 48 mm, S stands for steel shell
ICPt733448 model: square secondary lithium-ion battery, cathode material is cobalt, thickness is 0.7mm, width is 34mm and height is 48mm.
Different shape battery characteristics
Cylindrical battery is the oldest battery form. Its advantages include mature production process, high product yield, stable battery structure, wide application range, outstanding comprehensive performance and overall cost advantage. The disadvantages are also obvious. Cylindrical batteries are generally packaged in steel or aluminum, which are relatively heavy and have relatively low specific energy. Moreover, the safety is poor and the battery cycle life is short. And because of its small size, it can be used in many areas.
With the rise of power batteries, the popularity of square batteries in domestic applications is getting higher and higher. Moreover, compared with a cylindrical battery, the prismatic battery has a simple structure and a lighter weight than a higher energy. Since the square can be customized according to the requirements, there are many models on the market, and the process is difficult to unify, which is a challenge for cost.
There are also soft pack batteries on the market. Compared with cylindrical and square, the soft pack battery is made of aluminum plastic material. It only rises and does not explode, so it has better safety performance and more weight. The shape can be customized according to the needs, can be ultra-thin and can also be made into a cylindrical square or triangle. In addition, the soft pack battery has a larger capacity, a smaller internal resistance, and a longer life. In general, the soft pack battery has better performance. However, soft pack batteries currently have fewer models and higher development costs.
The game between 21700 and 18650 batteries
In accordance with China's latest implementation of the national standard document GB/T34013-2017 "Power battery power product specifications", continue to use the IEC name battery size model, stipulated "battery product size specifications general requirements", "dimension tolerance requirements" And "size range requirements", in which cylindrical battery sizes are 18650, 21700, 26650, 26700, 32700 and 32134; square batteries are available in a variety of sizes from 65mm to 217mm.
At present, in order to improve the energy density of the battery system and reduce the number of batteries, thereby reducing the cost, whether the square, cylindrical or soft-packed batteries have a tendency to expand the size of the single cell. More obvious is that the current cylindrical battery field has appeared 18650 to 21700/26650 upgrade phenomenon.
The 18650 and 21700 are currently two mainstream models. The new 21700 has four significant advantages:
(1) The battery cell capacity is increased by 35%. Taking the 21700 battery produced by Tesla as an example, after switching from the 18650 model to the 21700 model, the battery cell capacity can reach 3~4.8Ah, a substantial increase of 35%.
(2) The energy density of the battery system is increased by about 20%. According to the data disclosed by Stella, the energy density of the 18650 battery system used in the early stage was about 250Wh/kg. Later, the energy density of the 21700 battery system produced 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%. From the battery price information disclosed by Tesla, the 21700 battery power lithium battery system is priced at $170/Wh, while the 18650 battery system is priced at $185/Wh. With the 21700 battery on the Model3, only the battery system cost can be reduced by about 9%.
(4) The weight of the system is expected to drop by about 10%. As can be seen from the foregoing, the overall volume of the 21700 is greater than 18650. As the monomer capacity increases, the monomer energy density is higher, so the number of battery cells required at the same energy can be reduced by about 1/3, which reduces the difficulty of system management. It will also reduce the number of metal structural members and electrical accessories used in the battery pack, which further reduces the weight of the battery. After switching to a new 21700 battery, Samsung SDI found that the system was 10% lighter than current batteries.
Maintaining the high reliability and stable performance of the 18650 battery, the performance of the 21700 battery is greatly improved in all aspects than the 18650. In addition, compared with other battery models, the 21700 is similar to the more mature 18650 battery in terms of battery raw material selection, manufacturing process and technical process. Therefore, most of the 18650 and 21700 production lines are compatible. Some companies are more secure in making a fuss about the production line and moving the production line close to 21700 and 18650. Some companies' production lines are imported from abroad, but they are assembled on their own, so they can convert 18650 to 21700 at a lower cost.
21700 lift a change wave of battery products
The 18650 was originally developed by Japan's SONY Corporation, a standard lithium-ion battery model that was set in order to save costs. As a traditional battery cell, the 18650 is relatively mature in technology, with many manufacturers and strong adaptability. It can be digested in 3C digital, drone, power tools and other fields. With the rise of new energy vehicles, power batteries have become the focus of battery companies.
At the time of the production of electric vehicles, Tesla had only 18,650 batteries, but the 18,650 batteries were not born for power batteries. In 2008, Tesla's first model was launched in cooperation with Panasonic, using 18650 lithium cobalt oxide batteries as its power battery. On January 4, 2017, Tesla announced that it has started mass production of the new 21700 battery jointly developed with Panasonic, and emphasized that this is the highest energy density and lowest cost battery in the current mass production battery.
On January 9, 2017, Samsung SDI launched the new 21700 battery of the same specification at the appropriate time after Panasonic. LG also said that the 21700 battery will be mass-produced in 2021.
As a result, 21700battery has set off a battery product reform boom, and domestic and foreign companies are eager to develop and produce:
1. BAK battery
The energy density of the 18650-2.75Ah power battery cell has reached 240Wh/Kg, and it is working on the development of 21700 cylindrical power battery cells with high energy ratio. It is reported that it has the capacity for mass production and is expected to achieve mass production in 2018.
2. EVE Energy
On June 28, 2017, four 21700 and 18650 compatible fully automated production lines with an annual production capacity of 3.5GWh were put into operation. This is the first 21700 battery production line in China, which marks the official entry of China's cylindrical battery into the 21700 era.
3. Jiangsu Lishen
As a leading company in lithium-ion batteries, Lishen is still quite competitive in technology and products. In 2015, it began to supply large-scale 18650 ternary batteries to Jianghuai through Huaying Power. On July 20, 2017, its 21700 production line was officially put into production. This is the first production line customized for 21700 products in China.
4. Smart energy
The ternary 18650 lithium battery has a capacity of over 3GWh. In 2017, it will focus on 21700 batteries and build 6 automatic production lines of 21700-5Ah. The total planned size of 21700 is 7GW. At present, it has formed a cooperative relationship with domestic mainstream new energy smart car companies, and continues to expand strategic customers emerging Internet car companies.
5. Dynavolt tech.
After the first 18650 production line was successfully put into production at the Chun'an production base, the company invested in research and development to develop the 21700-type cylindrical battery core. On August 16, 2017, the 21700 battery production line of the 2GW capacity of the lion technology began construction, and it is expected to reach full production in the first half of 2019.
6. Zhihang New Energy
The existing 18650 battery production line has been upgraded, and 21700 lithium battery has been developed and has relevant production conditions. The 21700 lithium battery will be launched in due course according to the actual market conditions.
7. Chuangming New Energy
One of the earliest batches of ternary 18650 battery manufacturers in China, the power battery has many qualified car companies with superior qualifications. According to previous reports, the company has already started research and development of 21700 products in the early stage, and its 21700 production line is in the testing stage.
8. Tianpeng Energy
It is estimated that the company's total production capacity will reach 6GWh in 2018. The equipment equipped in the No. 2 production base is compatible with the production of the Model 21700, which can achieve any switching between the Model 18650 and the Model 21700. The energy density of the product can reach 200-240Wh/Kg.
9. Tianchen New Energy
The company's 18650 battery is mainly used in the "one high and one low" two fields, "high" refers to the high-end passenger car similar to Tesla; "low" refers to the mini car, logistics vehicle and so on below 100,000 Yuan. It is reported that its 21700 battery has been trial-produced and is expected to be officially put into production in 2018. The single-cell battery capacity is 4.5Ah.
10. Mottcell
It has been reported that it has successfully mass produced 21,700 batteries.
11. Anhui Taineng
Last year, it announced an investment of 5 billion Yuan to build and produce 21,700 power batteries.
12. Hengdian East Magnetic
Since 2016, it has been involved in the power battery industry. The power battery produced is mainly 18650. It is planned to start the layout of 21700 batteries from the second quarter of 2018.
13. Zhuoneng New Energy
One of the leading giants in the field of digital 18650, its product has been unanimously recognized by the OEM. Zhuoneng New Energy said that it will actively deploy 21700 battery production lines in the future to adapt to the changes in the lithium battery market.
14. Highstar
The overall production capacity has reached 2.6GWh, and the products involve three routes: cylindrical, square and soft. The company plans to invest in two power battery production lines in 2018, including a 21700 model power battery production line. It is estimated that by 2019, Haisida's total production capacity will reach 4GWh.
The page contains the contents of the machine translation.
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