This article takes ternary lithium batteries as an example, and analyzes the current technological level of domestic power battery companies based on three packaging systems: prismatic, cylindrical, and pouch, while also referencing the views of some experts. Without making unrealistic claims, it uses energy density as the standard to analyze the current technological level of domestic power battery companies.
Square Shell: CATL and BYD may not be lagging behind.
Official data shows that CATL's current energy density of prismatic cells has reached 240Wh/kg, and the technology plan is to increase the cell energy density to 300Wh/kg by 2020.
While increasing energy density through the use of 811 ternary cathodes and silicon/carbon hybrid anodes, sacrifices must be made in terms of cycle life, high-temperature performance, cost, and safety. Furthermore, the production process and environmental requirements are relatively stringent. An informed source revealed to this website that in 2017, CATL's mass-produced prismatic cells had an energy density between 190 and 210 Wh/kg, and this figure is likely to have increased to 210 to 230 Wh/kg in 2018.
As early as the beginning of 2017, CATL launched the "New Generation Lithium-ion Power Battery Industrialization Technology Development" project, developing lithium-ion power batteries with high-nickel ternary materials as the positive electrode and silicon-carbon composite materials as the negative electrode. In 2017, CATL's total production capacity was 17.09 GWh. The newly released prospectus shows that when the Huxi lithium-ion power battery production base project reaches full production capacity, CATL will add 24 GWh of capacity, bringing the total capacity to 41.09 GWh.
An insider at BYD revealed that the current energy density of BYD's mass-produced battery cells is 220Wh/kg, with a target of 300Wh/kg by 2020. Currently, BYD's total power battery production capacity is 16GWh, of which lithium iron phosphate batteries account for 9GWh and ternary lithium batteries account for 7GWh.
Internationally, prismatic cells are also a mainstay product of Samsung SDI. In 2017, Jung Se-woong, Vice President of Samsung SDI Corporation, publicly stated that Samsung SDI's power battery energy density was currently 250Wh/kg, and that it expected to reach a target of 350Wh/kg by 2023. It's possible that Samsung did achieve large-scale mass production of 250Wh/kg prismatic cells in 2017, but it's speculated that they may have used NCA ternary cathode materials.
There are many types of prismatic batteries, and battery manufacturers can customize them in terms of capacity, shape, and size according to customer requirements. Considering the differences in positive and negative electrode material formulations, the energy density of prismatic cells of the same specification is more comparable. The gap in cell energy density between leading domestic and international prismatic power battery manufacturers may be small; perhaps from this technological perspective alone, China may not be lagging far behind.
Cylinder: Can Bick surpass Panasonic?
As one of the few domestic companies that focuses on cylindrical power batteries, BAK told the author that its 2.75Ah power battery cell (18650) has reached an energy density of 240Wh/Kg, and plans to achieve 300Wh/kg in 2020.
Meanwhile, BAK is also committed to developing high-energy-density 21700 cylindrical power battery cells. According to official sources, compared to 18650 products, BAK's 21700 has a 35% increase in single-cell energy density (reaching 324Wh/kg?), and is currently capable of mass production, with large-scale production expected in 2018.
BAK has two major production bases in Shenzhen and Zhengzhou with a total annual production capacity of 8GWh; in 2018, the capacity will be expanded to 12GWh; and it is expected that by 2020, BAK's total annual production capacity will reach 20GWh.
According to information released by Tesla in 2017, Panasonic's mass-produced NCA18650 cylindrical power battery cells had an energy density of around 250Wh/kg, while the 21700 cells had already reached 300Wh/kg. If BAK could mass-produce 21700 cylindrical batteries in 2018, its energy density could surpass Panasonic's 2017 level, by nearly 8%.
Is this true? Panasonic has not publicly announced any new commercial technology advancements in 2018. If BAK can indeed achieve mass production of cylindrical cells with a capacity of 324Wh/kg in 2018, then it could become the world's highest energy density mass-produced power battery.
Soft packaging: Perhaps more significant for scientific research
Soft-pack batteries, as opposed to hard-pack batteries (square or cylindrical), are a common type of battery packaging and are therefore listed alongside cylindrical and square batteries.
Currently, CARNEE New Energy's mass-produced battery cells have an energy density of 220Wh/kg, and its 2018 products will reach 250Wh/kg. As of the end of 2017, CARNEE New Energy's total production capacity was 2GWh, and it will expand to 6GWh by the end of 2018.
In its investor relations activity record, Guoxuan High-Tech also disclosed that the company's undertaking of the National Science and Technology Ministry's major science and technology project on 300Wh/kg high energy density is progressing smoothly. It has developed ternary 811 soft-pack battery cells with an energy density of 302Wh/kg. It has started to build a pilot production line for related products and plans to start building the production line in 2019.
Tian Shuo, general manager of Beijing Keyi Power Technology Co., Ltd., analyzed that companies undertaking the research project on power battery cells under the major special project of the Ministry of Science and Technology have their own reasons for choosing ternary soft-pack batteries. "To achieve a 300Wh/kg battery cell, soft-pack batteries are definitely much easier than prismatic ones."
Soft-pack battery cells have poor mechanical strength, and their assembly process and thermal management requirements are relatively high, posing a certain challenge to the BMS design of vehicle manufacturers. Moreover, some core components are not yet domestically produced, but with the maturation of the industry chain, the prospect of large-scale domestic production is worth looking forward to.
Launching satellites is easier than doing practical work.
Although major battery companies have their own flagship products, they all engage in R&D to varying degrees on the three different battery systems: prismatic, cylindrical, and pouch. No one will put all their eggs in one basket. While the current market may dictate the types of products a company primarily promotes, in the long run, there will be no single, dominant technological path.
In today's power battery industry, news of capital injections and corporate mergers and acquisitions is constantly emerging, and various battery concepts and laboratory breakthroughs are emerging one after another. News such as "Charging for 1 minute can extend the range by 800km" frequently goes viral. Talking about technology without considering commercialization is meaningless. Each technical route has its own advantages and disadvantages. In the end, it is up to companies to do what they can, the market to choose, and the product to speak for itself.
