What are the differences between wet and dry diaphragms for power lithium batteries?

Comparison of the difference between wet and dry diaphragms for power lithium batteries 1. Because the process is simple, the investment in fixed assets is smaller than that of the wet method; however, it is difficult to control the temperature and other indicators of the dry method in the production process, and the wet method is simpler; 2. Dry method can make three-layer film, wet method can only make single-layer film; (The advantage of three-layer film is that the thermal shutdown temperature is 135 degrees, but the thermal stability temperature is 160 degrees, which can prevent thermal inertia. There is a space of 25 degrees. Safer) 3. In addition to different production processes, dry and wet methods use different raw materials. The raw materials used in the dry method have good fluidity and low molecular weight, so the high temperature can only reach 135 degrees, and it will shrink when exposed to heat. The safety is not suitable for high-power and high-capacity batteries; the wet method uses non-flowing, high-molecular-weight raw materials. The thermal shutdown temperature can reach 180 degrees, which can ensure the safety of high-power lithium batteries; the market status of wet and dry separators for power lithium batteries. The separator is used to separate the positive and negative electrodes of the battery to prevent short circuits and prevent short circuits. Let lithium ions pass through. Diaphragm is one of the most critical materials for lithium batteries, accounting for as much as 15-20% of battery cell cost. According to the process, the lithium battery diaphragm can be divided into two types: dry method and wet method. The advantages of the wet method compared to the dry method are the uniformity of the pore size and the higher air permeability, and the thinner thickness. Dry-process separators are mainly used in large-scale lithium iron phosphate power lithium-ion batteries, while wet-process separators are more widely used in ternary batteries that emphasize energy density. Wet diaphragm can greatly improve reliability and high temperature resistance through ceramic coating. We expect that as the penetration rate of ternary batteries increases, wet-process separators will gradually replace dry-process separators. In recent years, with the heating up of the power lithium-ion battery market, wet-coated separators have become more popular in China. There are even opinions in the industry that the wet-coated separators will inevitably dominate the future power lithium-ion battery separator market. On the contrary, those who support the dry process believe that domestic companies are just following the trend of Japan and South Korea. In fact, wet-process coated separators have some weaknesses. After long-term use, they may easily cause safety hazards for power lithium-ion batteries. Is the most suitable choice. From the perspective of market trends and the newly-added investment processing lines of diaphragm companies, wet-coated diaphragms currently have the upper hand. It is reported that there are qualitative differences between dry double drawing and dry single drawing, and there are not many companies with dry double drawing technology, and the market demand for dry double drawing coated diaphragms is also rapidly increasing. 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: How to improve the safety of lithium battery packs?