Prospects for the development of large cylindrical lithium batteries for energy storage



With the gradual improvement of the new energy industry's requirements for battery energy density and cost, cylindrical lithium-ion batteries show a trend of bigger and bigger size, Tesla took the lead in 2020 to propose the research, development and manufacture of 4680-type (46mm in diameter and 80mm in height) large cylindrical batteries, which has become a wind vane for the industry's development towards large cylindrical batteries.

In recent years, cylindrical lithium-ion batteries have gradually developed from the initial 18 series to 21, 26, 32 series, and 40 series have appeared in the market in the past two years. Global battery manufacturers have begun to layout large cylindrical batteries to meet the needs of the energy storage and power system sectors.

Large cylindrical batteries are favored by the market

Compared with small cylindrical batteries of 18, 21 and 26 series sizes, large cylindrical batteries are not only larger in size, but more importantly, there are some differences in internal structure. For example, 18, 21 and 26 series usually adopt conventional single lug design, while large cylindrical batteries utilize multiple lugs or full lugs technology.

In addition, large cylindrical batteries have obvious performance advantages over small cylindrical batteries. Advantage one, cylindrical batteries have higher technical requirements for BMS, large cylindrical batteries can reduce the difficulty of BMS control due to the reduction in the number of cells; Advantage two: the reduction in the number of cells can reduce the amount of structural components, the aperture of the bracket plate and collector plate becomes larger corresponding to reduce the weight, which can increase the efficiency of grouping, to make up for the shortcomings of low grouping efficiency of the small cylindrical batteries; Advantage three, due to the use of high-strength steel casing design of the large cylindrical batteries, which has little influence on the expansion of the pole group, and can be used to improve the performance of the battery. Advantage three, because the large cylindrical battery adopts high-strength steel shell design, its impact on the expansion of the pole group is small, small deformation, which makes the battery has excellent impact resistance, increasing its reliability in a variety of environments; Advantage four, multi-polar lugs or full lugs design makes the distance of electronic movement is greatly shortened to reduce the battery ohmic internal resistance, improve the performance of the battery multiplication rate; Advantage five: the large cylindrical battery because of the large single unit, is conducive to the industry to reduce the cost of the battery from the 21700 battery upgrades to the 46800 battery can be reduced by 14% of unit production. Upgrading from 21700 to 46800 batteries can reduce the unit production cost by 14%.

At the same time, large cylindrical battery technology development and manufacturing barriers are also higher. Larger volume of radial and axial geometric symmetry manufacturing difficulties, relatively harsh requirements for positive and negative electrodes, full lugs of kneading, welding, liquid injection and other technical difficulties, resulting in increased difficulty in manufacturing; secondly, because of the larger volume of the monomer, the internal heat dissipation of the electric core is more difficult.

Industry insiders believe that 2023 may become the first year of production expansion of large cylindrical batteries. in early 2023, Tesla announced the construction of two new factories near its production base in Nevada, U.S.A., of which the new battery factory will produce the latest 4680 batteries.

According to the incomplete statistics of China Chemical and Physical Power Supply Industry Association Energy Storage Application Branch, domestic mainstream battery companies such as Ningde Times, Yiwei Lithium Energy, Penghui Energy, Langtaitong Technology, Guoxuan Gaoke, Haichen Energy Storage, BAK, Poly New and other enterprises have been in the field of large cylindrical battery layout. Ningde Times said in the 2022 annual results briefing that the company has successfully developed 4680 and other large cylindrical batteries, in 2021, lithium-ion lithium-energy launched 40 series of large cylindrical batteries used in the field of household storage, peng hui energy 40 series of large cylindrical batteries in 2022 to start mass production, lang taitong technology's 32 series of large cylindrical batteries in 2016 to start mass production, the performance of the product has been energy storage, small power customers in various market segments. The mass production of domestic 4680 large cylindrical batteries is also just around the corner.

According to preliminary statistics, the domestic shipment of large cylindrical batteries in 2022 is close to 160 million units. And in the first half of 2023, the number has reached about 110 million units. These batteries are commonly used in key market areas such as lead-acid battery replacement, portable energy storage devices, household energy storage systems, low-speed electric vehicle power systems, and communication base station power backup.

Future Stars for Energy Storage Applications

In the next 5-10 years, with the gradual increase in the penetration rate of lithium batteries in the above markets and the release of large cylindrical battery production capacity, their shipments and market share will show rapid growth.

Taking household energy storage as an example, the new installed capacity of household energy storage in 2022 will be about 7.1GW, with a year-on-year growth of about 155%. 2022 global household energy storage will mainly focus on countries with high electricity prices, such as Germany, the United States, Japan, Italy and Australia.

The five countries mentioned above have added 5.45GW of new installations of household energy storage, which together account for about 77% of the global new installations of household energy storage. The global household energy storage penetration rate is expected to accelerate, and is expected to reach 28% by 2025.

Among them, the growth of the United States and Europe is the most considerable, the United States household energy storage penetration rate is expected to increase from 21% in 2022 to 36% in 2025, European household energy storage penetration rate is expected to increase from 18% in 2022 to 56% in 2025, the global household energy storage installed capacity is expected to reach 50GW in 2025.

In the field of power battery, according to the forecast of CICC, the market penetration rate of large cylindrical battery will reach 16% in 2025, and the global market demand for large cylindrical batteries will reach 144.2GWh-235GWh. Huatai Securities forecasts that the global installed capacity of large cylindrical batteries is expected to reach 429.0GWh in 2027, which corresponds to the overall market size of 214.48 billion yuan, with a CAGR of 110.0GWh in 2023-2027, and a CAGR of 10.0GWh in 2023-2027, which corresponds to a CAGR of 10.7%. CAGR of 110.7% in 2027.

With the growing market demand, many battery manufacturers have begun to increase the production capacity of large cylindrical batteries to meet the urgent demand for high-efficiency and high-reliability batteries in various industries. Not only in automotive manufacturing, 32 and 40 series large cylindrical batteries have been widely used in a variety of fields, such as household energy storage, portable outdoor power supply, electric two-wheelers, smart homes and robots.

The future development trend of large cylindrical batteries points to the 4680-type batteries. In a recent survey, YWL said that global mainstream car manufacturers are highly concerned about large cylindrical batteries, and the consensus that the 46 series of large cylindrical batteries will be one of the mainstream power battery in the future has basically been formed, but it will take time for the real large-scale application. In fact, many non-power battery manufacturers, including BAK and Lantech, are actively researching and developing 4680-type batteries to meet the needs of specific applications.

As technology continues to advance, the cycle life of large cylindrical batteries is being pushed toward 5,000 cycles or even higher, meaning that the batteries can withstand more charge/discharge cycles and thus provide longer service. Although square batteries also have application potential, they do not have the advantage in terms of manufacturing efficiency and cost in the capacity range below 50Ah, at which point large cylindrical batteries (not only limited to Type 4680, but also including sizes 32 and above) show their unique competitive advantages.

In conclusion, large cylindrical batteries, with their excellent performance stability, impact resistance, manufacturing process and cost advantages, show great potential for application and advantages in the field of energy storage. With the continuous progress of technology and market demand growth, large cylindrical batteries will play a more important role in the future of energy storage. Industry insiders believe that "the current large cylindrical battery industry chain is in the 'pre-dawn' stage of attack, the global large cylindrical battery market demand is expected to be about 23GWH in 2023, and is expected to exceed 250GWH in 2026."