The next spring of cylindrical batteries - 21700 lithium batteries?

which has its advantages and disadvantages. Among them, there are many types of cylindrical lithium batteries, such as 14650, 17490, 18650, 21700, 26500, etc.

The production process of cylindrical lithium battery is mature, the PACK cost is low, and the yield of battery products and the consistency of battery pack are high; The heat dissipation performance of the battery pack is superior to that of the square battery due to its large heat dissipation area; The cylindrical battery is convenient for combination of various forms, and is suitable for full layout of electric vehicle space design. However, cylindrical batteries are generally packaged with steel or aluminum shells, which are relatively heavy and have relatively low specific energy.

Tesla Model 3 selects 21700 battery, which is also a kind of lithium battery. "21" refers to the battery diameter of 21mm, "70" refers to the length of 70mm, and "0" means it is a cylindrical battery. Compared with the 18650 battery used by Tesla before, the 21700 battery is longer and thicker. It is reported that the energy density of the 21700 battery system used by Tesla is about 300Wh/kg, which is more than 20% higher than that of the 18650 battery used by the original Model S, the single capacity is increased by 35%, and the system cost is reduced by about 10%. It is understood that at present, Tesla's models use 18650/21700 cylindrical ternary lithium batteries.

Tianjin Lishen: It is the first in China to realize the mass production of 21700 batteries

Tianjin Lishen, founded in 1997, is a joint-stock high-tech enterprise with independent intellectual property rights and core technologies, focusing on the technical research, development, production and operation of lithium ion batteries. At present, it has an annual production capacity of 500 million Ah lithium-ion batteries. Its products cover six series of hundreds of models, including round, square, polymer batteries, power batteries, photovoltaic, and supercapacitors. Its applications cover the fields of personal electronic consumer products, electric tools, transportation, energy storage, etc.

In January last year, Tesla took the lead in proposing and planning to apply the 21,700 battery to Tesla's latest pure electric vehicle Model 3. Tianjin Lishen executives believed that the 21,700 battery was likely to become the future development trend of cylindrical power battery. The company's production focus shifted from 18,650 to 21,700 battery. After the feasibility study, The company selected the target product of the second phase project of East China Base as the next generation 21700 power battery (the first customized production line for 21700 products in China). The first phase project under construction is also directly adjusted to the 21700 production line.

In June, Suzhou Lishen 21700 batteries, a subsidiary of Tianjin Lishen, delivered more than 400000 batteries per day, with a monthly output of more than 10 million. With the continuous improvement of production capacity and pass rate, the monthly output of 20 to 25 million tubes can be achieved by the end of the year, and the annual output is expected to be 160 million tubes. Liu Yanlong, secretary-general of China Chemical and Physical Power Supply Industry Association, said, "This means that Tianjin Lishen has become the first company to mass produce 21700 cylindrical lithium-ion power batteries in China, and the second company in the world to achieve mass production of 21700 batteries after Tesla Panasonic."

Cylindrical battery: the trend of 21700?

After Tianjin Lishen, many power battery manufacturers began to upgrade from 18650 to 21700, and began to deploy 21700 batteries. However, at present, except for Panasonic, Tesla, Lishen and Far East Foster, which were jointly developed, most of the enterprises have not been able to really mass produce. Cai Qiang, deputy general manager of Far East Foster New Energy Co., Ltd., said, "Tesla has led the global trend of 18,650 batteries, and the application of 21,700 batteries in Tesla will undoubtedly be the next wind vane of cylindrical batteries."

According to incomplete statistics, battery manufacturers that clearly intend to enter the field of 21700 batteries at present include Yiwei Lithium Energy, Aoyang Shunchang, Bick Battery, Zhihang New Energy, Tianchen New Energy, Shanmu New Energy, Anhui Taineng, Zhuneng New Energy, Haisida, Chuangming New Energy, etc.

According to SMM analysis, the total installed capacity of cylindrical power battery of new energy vehicles in 2018 is about 7.11 GWh, accounting for 12.5% of the total installed capacity. Among them, the ternary cylinder is 5.0GWh, accounting for 66.9%; Lithium titanate cylinder 0.5GWh, accounting for 11.5%; Lithium iron phosphate cylinder 0.42GWh, accounting for 6.3%; Other types of battery cylinders totaled 1.19 GWh, accounting for 15.3%. The top five enterprises of cylindrical power battery are BYK Battery, Lishen, Guoxuan High Tech, Zhuhai Yinlong and Far East Foster.