Analysis of domestic lithium battery cell -Lithium - Ion Battery Equipment

Analysis of domestic lithium battery cell technology -Lithium - Ion Battery Equipment

On the premise of ensuring safety, improving energy density, reducing production costs, and improving product consistency are topics of widespread concern in the power battery industry. The production cost curve is constantly fluctuating, and product consistency is not easy to quantify. To evaluate the technical level of power battery companies, comparing the energy density of cells is the most intuitive method.

This article takes the ternary battery as an example, according to the three packaging systems of square shell, cylinder and soft package, with reference to the viewpoints of some people, without satellites, and analyzes the existing technical level of domestic power battery companies based on energy density.

Square shell: CATL and BYD may not be behind

Official data shows that the energy density of square shell cells in the Ningde era has reached 240Wh/kg at this stage, and the technical plan is to increase the cell energy density to 300Wh/kg by 2020.

While improving the energy density through the 811 ternary positive electrode + silicon/carbon hybrid negative electrode, the cycle, high temperature performance, cost, safety, etc. have to be sacrificed, and the production process and environmental requirements are also relatively harsh. People familiar with the matter revealed to the first electric network that in 2017, the energy density of square shell cells supplied in large quantities by CATL was between 190 and 210Wh/kg, and in 2018, it is likely to increase to 210-230Wh/kg.(Lithium - Ion Battery Equipment)

As early as the beginning of 2017, CATL launched the "New Generation Lithium-ion Power Battery Industrialization Technology Development" project to develop lithium-ion power batteries with high-nickel ternary material as the positive electrode and silicon-carbon composite as the negative electrode. In 2017, the total production capacity of Ningde era was 17.09Gwh, and the new version of the prospectus just announced shows that when the Huxi lithium-ion power battery production base project is put into production, Ningde era will add 24GWh of production capacity, and the total production capacity will reach 41.09GWh.

According to BYD insiders, BYD can mass-produce 220Wh/kg square shell cells by the end of 2018, and the goal is to achieve 300Wh/kg by 2020. Today, the total production capacity of BYD power batteries is 16GWh, of which lithium iron phosphate batteries account for 9GWh and ternary lithium batteries account for 7GWh.

Internationally, square shell cells are also the main product of Samsung SDI. In 2017, Zheng Shixiong, vice president of Samsung SDI Co., Ltd., publicly stated that the energy density of Samsung SDI power batteries is currently 250Wh/kg, and is expected to reach the goal of 350Wh/kg in 2023. Perhaps in 2017, Samsung has really achieved mass production of 250Wh/kg square shell cells, but it is estimated that NCA ternary cathode materials may be used.

There are many types of square shell batteries, and battery companies can customize in terms of capacity, shape and size according to customer requirements. Considering the difference in the formulation of positive and negative materials, the energy density between square-shell cells of the same specification is more comparable. The gap between domestic and foreign leading square shell power battery companies in terms of cell energy density may be very small. Perhaps from this technical point of view, China may not be too far behind.

Cylindrical: Can Piccolo surpass Panasonic?

As one of the few domestic companies focusing on cylindrical power batteries, BAK told the first electric network that the energy density of its 2.75Ah power battery cells (18650) has reached 240Wh/Kg, and plans to achieve 300Wh/kg in 2020 .

At the same time, BAK is also committed to the development of 21700 cylindrical power battery cells with high energy ratio. Officials revealed that compared with the 18650 product, the single energy density of the BAK 21700 has increased by 35% (to the level of 324Wh/kg?), and it has mass production capacity. It is expected to achieve mass production in 2018.

BAK's two major production bases in Shenzhen and Zhengzhou have a total annual production capacity of 8GWh; in 2018, the production capacity will be expanded to 12GWh; it is estimated that by 2020, the total annual production capacity of BAK will reach 20GWh.

According to the information released by Tesla in 2017, the energy density of the NCA18650 cylindrical power battery mass-produced by Panasonic is about 250Wh/kg, while the energy density of the 21700 unit has reached 300Wh/kg. If BAK can mass-produce the 21700 cylindrical battery in 2018, its energy density can surpass Panasonic's 2017 level by nearly 8%.



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