Analyze the role of lithium iron battery separator and the competitive characteristics of the lithium battery separator industry

In the structure of the iron-lithium battery, the separator is one of the key internal components. The diaphragm is made of plastic film, which can isolate the positive and negative electrodes of the battery to prevent short circuits; it can also block the current conduction in the lithium battery through the closed cell function when the battery is overheated. Today, commercial lithium-ion battery separators are still polyolefin microporous membranes. The function of lithium iron battery diaphragm The main function of the lithium iron battery diaphragm is to separate the positive and negative electrodes of the battery to prevent the two electrodes from contacting and short-circuit. In addition, it also has the function of allowing electrolyte ions to pass through. In addition, since the electrolyte is an organic solvent, the separator must also be resistant to organic solvents. The cost of the lithium iron battery separator accounts for about 1/3 of the battery cost. The performance of the diaphragm determines the interface structure and internal resistance of the battery, which directly affects the capacity, cycle performance and safety performance of the battery. A diaphragm with excellent performance plays an important role in improving the overall performance of the battery. At present, 60% to 70% of the diaphragm market mainly adopts the wet biaxial stretching process, because the wet biaxial stretching is more evenly balanced in the longitudinal and transverse directions. The wet method is mainly used for high-end diaphragms, and the dry method is used for low-end products. The ion conductivity of the iron-lithium battery separator is directly related to the overall performance of the battery. Its role in isolating the positive and negative electrodes enables the battery to limit the increase in current when the battery is overcharged or the temperature rises, preventing the battery from short-circuiting and causing an explosion. The self-closing protection function of the micropores plays a role of safety protection for battery users and equipment. Competitive characteristics of the lithium battery separator industry Lithium battery separators are generally divided into dry process and wet process according to the process. Therefore, the separator products are also divided into two types of dry process separators and wet process separators. From the perspective of technological progress, at present, my country's lithium battery separators have made major breakthroughs in the dry process, and have world-class manufacturing levels. The wet separator process technology has also been continuously improved. In recent years, the production capacity and output have increased steadily. With the continuous development of wet process technology, the competitive landscape of my country's lithium battery diaphragm industry has also undergone some changes. Feature 1: The proportion of wet-process diaphragm production has increased year by year. From the perspective of the process itself, lithium battery dry-process diaphragms and wet-process diaphragms have their own advantages and disadvantages. Dry-process diaphragms have greater advantages in terms of production process, cost, environmental protection, and economy. The French diaphragm has the advantages of low short-circuit rate, wide controllable range of porosity and air permeability. Judging from the current market applications, from the perspective of the choices of global lithium battery companies, dry-process separators and wet-process separators coexist. However, in recent years, as the proportion of ternary lithium batteries has increased, the proportion of wet diaphragm production has also steadily increased. The latest data show that in 2017, the domestic production of wet-process diaphragms reached 806 million square meters, accounting for 56%, and the share exceeded that of dry-process diaphragms. Due to the respective characteristics of dry and wet diaphragms, the demand for wet diaphragms will gradually expand in the future, but it will not completely replace dry diaphragms in a short period of time. Feature 2: High Concentration of Shipments. In terms of shipment volume, in 2017, my country’s dry-process and wet-process diaphragm companies have a relatively high level of corporate concentration, especially for wet-process diaphragms, the top three companies’ shipments. The proportion reached 71%, and the top five accounted for 87%; the top three companies in the dry process membrane accounted for 42%, and the top five accounted for 55%. Feature 3: Obvious regional production capacity Judging from the current regional distribution of lithium battery separator materials companies in my country, the overall concentration is relatively high, mainly in East China and Central China, with the production capacity ratio reaching 48% and 27% respectively; the production capacity in South China There are also 10%, and other regions are all below 10%. Feature 4: Accelerating production capacity expansion and intensifying competition in the future According to the data, as of the end of 2017, the domestic production capacity of lithium battery separators has been confirmed to be about 2.9 billion square meters. According to the current production capacity, the major companies with larger production capacity are Hunan Zhongli, Shanghai Enjie, Xingyuan Materials, Zhongxing New Materials, Tianjin Donggao, Suzhou Jieli, Henan Yiteng, etc., with a production capacity of 200 million square meters. Above, the total production capacity is 1.928 billion square meters, accounting for more than 67%. In the future, the total planned new production capacity of domestic lithium battery separator companies will exceed 6.2 billion square meters. With the existing capacity, my country's lithium battery separator production capacity will exceed 9 billion square meters. However, with the increase of market participants, the future industry competition of lithium battery separators will further intensify. my country’s lithium-ion battery separator technology gap Lithium battery separator is the part with the highest technical barriers among the four major materials. Its cost is second only to cathode materials, about 10% to 14%. In some high-end batteries, the cost of separators is even Reached 20%. my country's lithium-ion battery separators have made major breakthroughs in the dry process, and currently have the world's first-class manufacturing level. However, in the field of wet diaphragms, domestic diaphragm companies are limited by many factors such as process and technology, their product level is still low, and production equipment mainly relies on imports. There is a big gap between the thickness, strength, and porosity consistency of diaphragm products in my country and foreign products, and the consistency of product batches needs to be improved. The above is the function of the lithium iron battery separator and the characteristics of industry competition. The output value of the separator has the fastest growth rate in the four major segments of lithium batteries! It directly determines the performance and safety of lithium batteries. At the same time, lithium battery separators have always been the product with the highest gross profit among the four major materials.