This round of large-scale capacity expansion by diaphragm manufacturers is inherently driven by the demand for power batteries. From the technical point of view, wet + coating dominates the response to the high energy density development needs of power batteries. The large-scale expansion reflects the cost reduction needs of battery manufacturers.
The separator is one of the most critical inner layer components in the power battery structure. Its main function is to separate the positive and negative plates in the battery to prevent the positive and negative plates from directly contacting and causing short circuits. At the same time, because the separator has a large number of penetrating micropores, the positive and negative ions in the battery can pass freely in the micropores, and migrate between the positive and negative plates to form the internal conductive circuit of the battery, while the electrons migrate between the positive and negative electrodes through the external circuit. Generates current for use by electrical equipment.
Therefore, the performance of the separator not only determines the interface structure and internal resistance of the battery, but also directly affects the battery capacity, cycle, and safety performance. The separator with excellent performance has an important role in improving the overall performance of the battery.
In recent years, driven by the subsidy policy for new energy vehicles, the new energy vehicle industry has developed rapidly, and the total installed capacity of batteries has grown rapidly. At the same time, the positive / negative electrode materials and electrolytes in the four main materials of power batteries have gradually been domestically produced, and the localization rate of separators has continued to increase, from 90% in 2017 to 93% in 2018. And gradually move towards the exit.
With the acceleration of the installed capacity of power batteries and the acceleration of the domestic production of separators, the domestic separator output reached 2.01 billion square meters in 2018, a year-on-year increase of 39.7%. The time has entered 2019, and with the new round of capacity expansion of power batteries, diaphragm companies have also set off a large-scale wave of production expansion. According to statistics, in 2019, the newly built or newly commissioned diaphragm reached 4.118 billion square meters.
Frequent expansion of diaphragm manufacturers
On the morning of March 18, the groundbreaking ceremony for the second phase of the QDZK lithium battery new material project was held in Qingdao International Economic Cooperation Zone. With a total investment of RMB 1.7 billion, the project will annually produce 1 billion square meters of lithium battery separators with an output value of RMB 5.6 billion. It will build a leading domestic and northern largest separator production R & D base.
It is understood that QDZK New Materials Co., Ltd. is an industry leader in the research and development and production of separators for wet lithium-ion batteries. It has 42 national patents. It was identified as the first (set) major technical equipment in China.
On April 29th, CZMZ Diaphragm Science and Technology was responsible for the construction of a 50 million square meter dry-process lithium-ion battery separator project. As of now, the two production line related equipments of the project have been debugged and completed trial production, and they have officially started production. It is understood that the total investment of the project is 79.91 million yuan, mainly including 2 dry-process diaphragm production lines.
On May 30, ZCKJ Lithium Membrane Technology Co., Ltd. plans to invest 1.547 billion yuan to build a "power lithium-ion battery separator production line with an annual output of 408 million square meters" project. The project will invest in the construction of 6 lithium battery separator base film production lines with a single-line production capacity of 68 million square meters per year, and 10 coated separator production lines with a total capacity of 408 million square meters per year (including 200 million square meters of coated separators). Wet synchronous drawing process with independent intellectual property rights.
On June 28, QHBJ New Material Technology Co., Ltd. rolled off 2 production lines of lithium battery separator products. The project plans to build 6 separator production lines and 2 coating production lines. It is expected to produce 400 million square meters of power and energy storage lithium battery separators This project uses Japanese diaphragm production technology-wet two-way asynchronous stretching process.
Supported by a team of Japanese R & D experts and manufactured by foreign advanced film processing equipment, this process technology currently leads the world. The project can effectively alleviate the predicament of high-end separators on the market that rely on imports, improve the technical level and large-scale production capacity of lithium battery separators in China, and provide technical support for the new energy vehicle industry and even the clean energy layout of Qinghai.
On July 1, SHEJ New Materials Technology Group ’s lithium battery separator project. In order to increase the capacity of lithium battery separators, a new phase 2 lithium battery separator project was built in the new material industry base. The total investment for the second phase project was 2.8 billion yuan. Automatic film production line and 16 coating production lines are mainly used for the manufacture and sales of lithium battery wet base film and functional coating diaphragm.
The main products of SHEJ new material project are lithium battery wet base film and functional coating diaphragm. Wet film is mainly produced by wet process route. It has more than 20 patented technologies including lithium battery isolation film and film surface deformation detection device. The product has reached the international leading level in parameters such as porosity, tensile strength, heat shrinkage, and closed cell temperature. After the Wuxi project is completed and put into operation, the annual wet-process diaphragm will be close to 2.5 billion square meters, becoming the world's largest wet-process diaphragm. manufacturer.
In addition, in May this year, SHEJ also raised no more than 1.6 billion for 8 million film production lines of the 400 million square meter lithium-ion battery separator project (Phase 1) produced by subsidiary JXRN and 8 WXEJ new material industrial base projects Lithium battery separator base film production line and 16 lithium battery coating film production lines. It is planned to be completed within the year.
SZXY Membrane Technology Group implements both wet and dry expansion strategies. It is understood that SZXY has 210 million square meters of dry production capacity and 110 million square meters of wet production capacity. At the same time, the company set up a "Super Coating Factory" project to continue to expand the capacity of dry diaphragms, and lay out coated diaphragms to target the high-end market. Projects under construction include 8 dry-line production lines under construction, which are expected to add an additional 400 million square meters of annual production capacity to the existing basis after the production capacity is reached, and 8 wet-process diaphragm production lines. 360 million square meters.
Features of diaphragm capacity expansion
The separator is divided into a wet separator and a dry separator. The wet separator is more excellent in terms of thickness uniformity, mechanical properties, breathability, and physical and chemical properties, which is beneficial to the absorption and retention of the electrolyte and improves the charge and discharge and circulation of the battery. Capacity suitable for making high capacity batteries. The advantages of dry process diaphragms are mainly reflected in good thermal stability, simple equipment, small investment, short cycle, low cost, large energy consumption, production efficiency, and difficulty in production.
However, judging from the expansion or new production projects of diaphragm manufacturers this year, wet-process diaphragms dominate. Including SHEJ Group, QDZK, ZCKJ, QHBJ, all newly built or newly-launched wet-processed and coated diaphragms, and SZXY also newly-launched 360 million square meters of wet-processed diaphragms; the capacity of newly-built or newly-laid wet-processed diaphragms reached 36.68 square meters , Accounting for 89% of the total expansion capacity.
At the same time, the expansion of the capacity of wet diaphragm also has its outstanding feature, that is, the project has a large scale and the smallest capacity is SZXY's 360 million wet diaphragm project. In comparison, the scale and number of dry diaphragm expansion will appear smaller. Only SZXY has a new capacity of 400 million square meters of dry diaphragm production and HBCZ has a new capacity of 50 million square meters of dry diaphragm production. About 10% of new expansion capacity.
According to the calculation of the diaphragm manufacturer HBCZ, 1Gwh power battery requires about 20 million square meters of diaphragm. Judging from the newly expanded production capacity of 4.118 billion square meters, it can provide separator supply for 200Gwh power batteries. It is much larger than the installed capacity of power batteries in 2018. Only the 1.5 billion square meter separator capacity expanded by a company in the SHEJ Group can meet the needs of 56.89 Gwh of installed power batteries in 2018.
The inherent logic behind the capacity expansion of diaphragm manufacturers
Although the diaphragms produced by the two processes have their own characteristics, there is no clear distinction between advantages and disadvantages. However, by coating the base film with ceramic alumina, PVDF, aramid, and other adhesives, the wet diaphragm can greatly improve the thermal stability of the diaphragm, reduce the high-temperature shrinkage rate, and prevent the pole pieces from being exposed due to the large shrinkage of the diaphragm. The only thermally stable short board, the product performance is fully ahead of the dry film.
In general, wet diaphragms have greater advantages in performance than dry diaphragms, especially the thermal stability short board is successfully solved by the wet + coating method, and it is thinner and lighter than the dry diaphragm, so It is often used in high energy density power batteries. From the perspective of the capacity expansion of membranes based on the wet process, high energy density is still the mainstream of development of power battery manufacturers.
Although in terms of cost, the wet separator is higher than the dry separator. However, the cost ratio of diaphragms in electric vehicles is not high. The marginal impact of the wet method instead of the dry method on the cost of automobile companies or battery companies is not large, and it is strongly driven by downstream customers. With the development of ceramic coating technology, ceramic separators have changed the defects of low melting point and poor safety of wet separators in the past, and the application range has continued to expand.
In fact, in the new energy subsidy policy in 2019, in general, the subsidy amount has fallen sharply, but the requirements for the energy density of power batteries are higher. Coupled with the anxiety of industry mileage, high energy density technology routes such as high nickel ternary have become mainstream and development direction. Due to the bi-directional stretching technology of the wet separator, the separator can be made thinner and stronger, making the capacity of the battery larger, which is in line with the development of the battery industry.
This year, many power battery manufacturers announced that they have achieved mass production of high-nickel 811 batteries. CATL's high-nickel 811 batteries have been successfully installed in BMW x1 plug-in hybrid vehicles. Other large domestic battery manufacturers are also accelerating the realization of high-nickel 811. Mass production installed. Therefore, the membrane manufacturer's preference for wet method when expanding capacity is in line with the high energy density development direction of power batteries.
At the same time, the large-scale capacity expansion of diaphragm manufacturers also meets the cost reduction requirements of power batteries. This year, the average subsidy for new energy vehicles in the new regulations has fallen by more than 50%, and power batteries account for about 1/2 of the total vehicle cost. The value is the largest, and it is also considered to have the most room for price reduction. Under the pressure of cost reduction, Power batteries are the first to be affected, and materials companies are also affected.
Previously, the separator had the highest gross profit among the four main materials of power batteries. According to statistics, the gross profit of first-line wet-process diaphragm companies in 2018 is about 30% ~ 45%, and the gross profit of first-line dry-process single-pull diaphragm companies is about 35% ~ 50%. However, due to the cost reduction of power batteries, battery factories have continued to lower prices on raw materials, and the price of domestic separators has fallen by more than 15% since the end of 18 to April 1919.
For separator manufacturers, when the wet method has become the development direction of power batteries, the only way to meet the price reduction requirements of battery factories is to expand the scale and reduce the unit cost.
Overall, this large-scale expansion of diaphragm manufacturers is inherently driven by the demand for power batteries. From the technical point of view, the dominance of wet method + coating is to meet the development needs of high energy density of power batteries, and the large-scale expansion reflects the cost reduction needs of battery manufacturers.