Original title: Large cylindrical battery is in the ascendant
Text | Lin Shuijing, an intern reporter of this newspaper
"Cylindrical battery with the highest safety" "Large cylindrical products can emit more than 90% of the electricity at room temperature at minus 30 °C"... Recently, at the power battery forum hosted by the China Electric Vehicle 100 People's Association, power battery companies such as BAK Battery and Ewell Lithium Energy have proposed that the large cylindrical battery will be the development direction of high-end electric vehicle power batteries in the future.
"The Ultimate Technical Direction of Power Batteries"
Fan Wenguang, vice president of Shenzhen BAK Power Battery Co., Ltd., introduced that BAK batteries have been studied in the field of cylindrical batteries for 17 years, and before Tesla proposed 4680 cylindrical batteries (cylindrical batteries with a diameter of 46mm and a height of 80mm), it was judged that large cylindrical batteries would be the optimal solution for high-end electric vehicle batteries. Compared with cylindrical batteries of the 18 series and 21 series, the large cylindrical batteries not only have an increase in size, but also have certain structural differences. Meanwhile, the 18 Series and 21 Series size batteries use conventional polar ears, while large cylindrical batteries use full polar ears. After testing, the cell using the omnipolar ear is 65%-80% lower than the internal resistance of the traditional unipolar ear battery of the same system, which means very high power input and output.
It is understood that there are currently 3 technical routes for power batteries - cylindrical batteries, square batteries and soft pack batteries. For the safety of large cylindrical batteries, Fan Wenguang introduced: "The cylindrical battery cells are small and disperse the risk, while each single body is protected by a steel or aluminum shell and an independent pressure relief device. In addition, the cylindrical cells in the battery pack are generally arranged in a honeycomb shape, there is a gap between the cells, and there is also a large heat exchange area between the cell and the outside, which means that after any single cell runs out of thermal control, it will not spread to the surrounding cells, thus ensuring thermal safety at the package level. ”
Liu Jincheng, chairman of Huizhou Yiwei Lithium Energy Co., Ltd., also pointed out at the forum: "The 46 series cylindrical batteries (4680 and 4695 batteries) have outstanding safety and economy, do not deform, and are expected to become the ultimate technical direction of power batteries. ”
Mass production will be made next year
Although the advantages of cylindrical batteries are outstanding, looking at the current domestic power battery market, its performance is not outstanding.
It is understood that in the top 10 models of the domestic new energy vehicle sales list in 2021, only Tesla has chosen a cylindrical battery. "At present, square batteries still occupy the mainstream position in the domestic market." Zhang Xiang, a researcher at the Automotive Industry Innovation Research Center of North China University of Technology, believes that square battery suppliers and industrial chains are well-supported, with good economic benefits, many resources, many alternative suppliers, and low overall industry costs. In contrast, the cost of domestic manufacturing cylindrical and soft pack batteries is higher.
At the same time, Fan Wenguang said that at present, the large cylindrical power battery is generally in the promotion stage from design verification to engineering verification, "after the design and other work in 2021, we have entered the stage of batch delivery of samples, and the performance standard even exceeds expectations." It is expected that small-batch mass production will be held in the second half of this year, large-scale mass production and supply will be realized next year, and 80 GWh of production capacity will be added at home and abroad in stages in the future. ”
The industrial chain needs to work together
Fan Wenguang introduced: "In 2021, the global sales of electric vehicles will exceed 7 million, according to conservative forecasts, by 2025, the number will exceed 20 million, the corresponding power battery demand will exceed 1600 GWh." Judging from customer needs and combined with industry information, large cylindrical batteries will account for at least 30% of the share, that is, 480 GWh, which exceeds the total demand for global power batteries in 2021. ”
"On the surface, although the manufacturing process of large cylindrical batteries is more concise and efficient than that of traditional small cylindrical batteries and other forms of batteries, it has put forward higher technical requirements for equipment suppliers, chemical material suppliers and electric vehicle companies." Fan Wenguang said frankly.
For the technical route of future power batteries, Zhang Xiang believes: "Since last year, the installed capacity of lithium iron phosphate batteries has exceeded that of ternary lithium batteries. In January this year, the market share of lithium iron phosphate batteries reached 55%, and in February increased to 63%, the future lithium iron phosphate batteries will be the mainstream technical route, so the pattern dominated by square batteries will last for a long time, and the large-scale development of cylindrical batteries needs to continue to improve the industrial chain. ”
Fan Wenguang also said: "The large cylindrical battery process is simple and highly standardized, as well as the characteristics of reduced structure at the whole package level and simple groups, etc., have certain advantages in the overall cost, if you want to realize the advantages, you need all aspects of the industrial chain to work together to achieve a large-scale inflection point." ”
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Produced by | China Energy News (ID:cnenergy)
Trainee Editor | Li Zemin
Editor-in-charge | Yan Zhiqiang