Prospects and development trends of the domestic lithium battery pack diaphragm industry

In the structure of the lithium battery pack, the diaphragm is one of the key internal components. How the performance of the diaphragm directly affects the cycling, capacity, and safety performance of the lithium battery pack, and also has a significant impact on the overall performance of the battery. Introduction to the diaphragm The specific function of the diaphragm is to separate the positive and negative electrodes of the lithium battery pack, prevent the two poles from being short-circuited due to contact, and also has the function of allowing electrolyte ions to pass through. The diaphragm has a large number of tortuous micropores, which can effectively ensure the free passage of lithium ions to form a loop. At the same time, it can also prevent the positive electrode and the negative electrode from contacting by closed cells when the lithium battery pack is overcharged or the temperature is too high. To achieve the role of insulation. The material of the diaphragm is non-conductive, and its physical and chemical properties have a great influence on the performance of the battery. Different types of batteries have different separators. According to different production processes, in general, there are two distinctions between dry and wet diaphragms. The dry process is mainly used in China, while the wet process is more common in foreign countries. The development status of domestic separators. In recent years, with the successful localization of separators, the price has dropped greatly, and the proportion of the total cost of lithium battery pack materials has also dropped a lot, generally ranging from 7% to 7%. About 15%. In the lithium iron phosphate battery pack, since the unit cost of the positive and negative materials is relatively low, the proportion of the overall cost of the separator is higher than that of other types of lithium batteries, accounting for about 15% . Among the constituent materials of lithium battery packs, the technical content required by the separator and the gross profit margin are relatively high. Among these materials, the diaphragm is the last material to achieve localization. In recent years, with domestic research institutes' breakthroughs in lithium battery preparation technology, coupled with national policy support, and large amounts of capital investment by manufacturers, China's global market share of lithium battery pack separators has increased rapidly. Compared with foreign countries, in the past, the production process of domestic diaphragm manufacturers was mainly dry stretching. However, in recent years, with the continuous improvement of domestic diaphragm companies in the wet production process, the output and performance of wet diaphragms are getting closer and closer to foreign levels. With the development of technology, domestic diaphragm companies have expanded their production of wet-process diaphragms, and the domestic diaphragm market has undergone great changes compared to the past. In China, the largest demand for diaphragms is the power battery market. Relevant personnel have measured the total demand of the China Disabled Persons' Federation and the total demand of the domestic diaphragm. Last year, the domestic diaphragm production was generally close to the demand. Considering that the demand for wet-process diaphragms in the market has grown significantly faster than that of dry-process diaphragms, the supply and demand pattern of wet-process diaphragms on the market is still tight. From this year onwards, according to calculations, the total output of domestic diaphragms will exceed the demand when all enterprises go into production smoothly. Prospects of the domestic separator industry. With the increase in the supply of lithium battery pack separators on the market, competition in the separator market will intensify in the future. In particular, the production capacity of wet-process separators will be greatly increased, which will affect the production of wet and dry separators. Product prices are under greater pressure. On the one hand, there will be competition among domestic diaphragm companies. On the other hand, the development of wet-process diaphragms will inevitably squeeze the market space of dry-process diaphragms. As time goes by, it will be an inevitable trend that the price of diaphragm products will fall. With the decline in prices and the expansion of domestic diaphragm production capacity, the industry scenario for lithium battery pack diaphragms will become clearer.