Lithium battery separator industry characteristics and type analysis

Characteristics of Lithium Battery Separator Industry Lithium battery separator. jpg The dual nature of ice and fire is the most prominent feature of the lithium battery separator industry in recent years. On the one hand, the diaphragm industry affixed with high-tech barriers and high-margin labels has poured in a large amount of capital. The enthusiasm for capital trading in the field of lithium battery diaphragms has been unprecedentedly high. On the other hand, many diaphragm companies that have received capital assistance continue to gather large-scale processing and new production. Under the background that power lithium-ion batteries are required to reduce costs and improve quality, the overall price and gross profit of the diaphragm industry have seen a cliff diving, not high-end diaphragms. Production is in the quagmire of price wars. The characteristics of the lithium battery separator industry determine that the supply will be highly concentrated, the prices of low-end products will be reduced, and the supply of mid-to-high-end products is still in short supply. There is huge room for substitution of imports, and the profitability will remain at a relatively high level. From the perspective of industry characteristics, capital and technology are intensive, and barriers to entry are high. The technical difficulties of functional films are often reflected in the current raw materials, production equipment or processing technology. The diaphragm has relatively high technical difficulties in these three aspects. The continuous advancement of lithium battery capacity and production technology requires diaphragm companies to continuously develop and improve quality. What types of lithium battery separators are based on the differences in physical and chemical characteristics. Lithium battery separators can be divided into: woven membranes, non-woven membranes, microporous membranes, composite membranes, membrane paper, and laminated membranes. Polyolefin materials have excellent mechanical properties, chemical stability and relatively inexpensive characteristics. Therefore, polyolefin microporous membranes such as polyethylene and polypropylene have been used as lithium battery separators in the early stage of lithium battery research and development. Although in recent years there have been researches using other materials to prepare lithium battery separators, such as the phase inversion method using polyvinylidene fluoride as the bulk polymer to prepare lithium battery separators, and the study of cellulose composite membranes as lithium battery separator materials. Although there are many types, so far commercial lithium battery separator materials have mainly used polyethylene and polypropylene microporous membranes. The characteristics of the two materials of polyethylene and polypropylene 1. Polypropylene is relatively more resistant to high temperatures, and polyethylene is relatively resistant to low temperatures. 2. The density of polypropylene is lower than that of polyethylene. 3. The melting point and closed cell temperature of polypropylene are higher than that of polyethylene. 4. Polypropylene The product is more brittle than polyethylene. 5. Polyethylene is more sensitive to environmental stress. The microporous structure of the separator is critical to the safety of the battery. When the battery is overcharged or the temperature is too high, the separator will close the pores and form an open circuit inside the battery. , Limit the current rise, and the alert temperature further rises. The closed cell temperature of the separator is related to the substrate used. The closed cell temperature of the polypropylene separator is higher, and the melting temperature is also very high; the closed cell temperature and the melting temperature of the polyethylene separator are both low. The fusing temperature means that at this temperature or above, the diaphragm completely melts and shrinks, and the internal short circuit of the electrode appears high temperature, causing the battery to disintegrate or even explode. Therefore, the safety of lithium batteries usually requires a lower closed cell temperature and a higher fusing temperature. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Detailed explanation of the advantages and disadvantages of graphene batteries