Nitrogen generator continuously supports the production of lithium battery separator films

In the rapidly advancing technological era, batteries, as the power source for numerous devices, have their performance and quality under close scrutiny. Battery separators, as a crucial component of batteries, play a vital role in their safety, stability, and service life. In the production process of battery separators, nitrogen generators are quietly playing an indispensable role, providing strong assurance for the production of high-quality separators

I. Strict Environmental Requirements for Battery Separator Production

      A battery separator is a thin film with a microporous structure. Its main function is to separate the positive and negative electrodes within a battery, prevent short circuits, and simultaneously allow ions to pass through, ensuring normal battery charging and discharging. To ensure these properties of the separator, the production process demands extremely strict environmental conditions. Any tiny impurity, moisture, or oxygen can affect the microporous structure of the separator, thereby reducing battery performance. Therefore, creating a clean, dry, and oxygen-free production environment has become crucial for battery separator manufacturing

II. Application Scenarios of Nitrogen Generators in Battery Separator Production

(I) Nitrogen Protection during Raw Material Storage and Transportation

In the production process of battery separators, the quality of raw materials directly impacts the performance of the final product. Many raw materials used for separator production, such as polyolefin resins, are highly hygroscopic and easily oxidized in the air. The high-purity nitrogen produced by nitrogen generators can be used to purge raw material storage tanks and conveying pipelines, expelling air to prevent contact between raw materials and oxygen and moisture. This effectively prevents raw materials from deteriorating, ensures their stable performance, and provides reliable material assurance for subsequent production processes. For example, in a large battery separator manufacturing enterprise, by installing nitrogen generators in the raw material storage area and continuously purging storage tanks containing polyolefin resins with nitrogen, the phenomena of moisture absorption and oxidation of raw materials have been significantly improved, and the product reject rate has been greatly reduced

(II) Creating an Inert Gas Atmosphere during the Production Process

Extrusion molding process: During the extrusion molding of separator membranes, the polymer melt easily reacts with oxygen in the air under high-temperature conditions, leading to degradation and aging, which affects the mechanical properties and microporous structure of the separator. At this point, the nitrogen supplied by the nitrogen generator can form an inert gas protective atmosphere at key parts such as the extruder die head, die, and cooling zone, effectively isolating oxygen and ensuring that the polymer melt forms in a stable environment. For instance, by setting up a nitrogen purging device at the extruder die head, blowing nitrogen at a certain flow rate and pressure onto the die head surface to prevent air entry, product defects caused by oxidation can be significantly reduced, and the surface quality and uniformity of the separator can be improved

Stretching process: Stretching is a crucial step in the production of battery separators to form a microporous structure. During the stretching process, precise control of temperature, humidity, and the gas environment is required. The inert nature of nitrogen makes it an ideal protective gas in the stretching process. It not only prevents the separator surface from being oxidized during stretching but also helps control the temperature uniformity in the stretching zone by adjusting the nitrogen flow rate and temperature, allowing the separator to form a more regular and uniform microporous structure during stretching, thereby improving the separator's air permeability and ion transfer efficiency. A well-known battery separator manufacturer equipped its stretching workshop with multiple nitrogen generators. By continuously purging the stretching area with nitrogen, the consistency of the product's microporous structure was greatly enhanced, and the product's competitiveness in the market was significantly strengthened

Heat setting process: The heat setting process is used to stabilize the microporous structure and dimensions of the separator. During high-temperature heat setting, if oxygen is present, the separator may undergo thermal oxidative degradation, leading to a decline in membrane performance. The high-purity nitrogen provided by the nitrogen generator can create an oxygen-free environment inside the heat setting equipment, effectively preventing thermal oxidation reactions and ensuring that the separator has stable performance and dimensional accuracy after heat setting. For example, by introducing nitrogen into the heat setting oven to control the oxygen content at a very low level, the thermal stability of the separator can be significantly improved, and the product will exhibit smaller dimensional changes during subsequent use, better meeting the requirements of battery production

(III) Nitrogen Filling in the Product Packaging Stage

Battery separators also require nitrogen protection during the packaging process. If air remains inside the package after the separator is packaged, the oxygen and moisture within it may adversely affect the separator during long-term storage. By using a nitrogen generator during the packaging stage to fill the package with nitrogen and displace the air, a low-oxygen, dry environment can be created, effectively extending the separator's shelf life and ensuring its performance remains undamaged during storage and transportation. For instance, some high-end battery separator products adopt vacuum nitrogen-filled packaging, where the packaging bag is first vacuumed before filling it with high-purity nitrogen and then sealing it. This packaging method can protect the separator's quality to the maximum extent, allowing it to maintain good performance even after long-term storage

IV. Significant Advantages of Nitrogen Generators in Aiding Battery Separator Production

(I) Enhancing Product Quality

By providing nitrogen protection throughout the entire production process, nitrogen generators effectively reduce the impact of impurities such as oxygen and moisture on battery separators, making the product's microporous structure more uniform and stable, and significantly improving its mechanical properties and chemical stability. This not only enhances the product quality of battery separators but also improves their performance in batteries, laying a solid foundation for increasing the overall performance and safety of batteries

(II) Reducing Production Costs

Compared to traditional methods of using bottled nitrogen or liquid nitrogen supply, on-site nitrogen generation with nitrogen generators offers significant cost advantages. Nitrogen generators can produce nitrogen in real-time according to production demands, avoiding the high costs associated with purchasing, transporting, and storing bottled or liquid nitrogen. Furthermore, the operating costs of nitrogen generators are relatively low, and equipment maintenance is simpler, which can effectively reduce enterprise production costs and improve economic efficiency

(III) Enhancing Production Flexibility and Reliability

Nitrogen generators can flexibly adjust nitrogen output and purity according to the nitrogen consumption and purity requirements of different processes on the battery separator production line, achieving on-demand supply. This high degree of flexibility allows the production process to better adapt to changes in different product specifications and production technologies. Furthermore, as on-site nitrogen generation equipment, nitrogen generators ensure the continuity and stability of nitrogen supply, avoiding production stoppages caused by interruptions in external gas sources, thus greatly enhancing production reliability

In the battery separator film production industry, nitrogen generators are injecting strong impetus into the industry's development with their unique advantages and diverse application scenarios. With continuous technological advancements and the battery industry's sustained growth in demand for high-performance separator films, nitrogen generators will inevitably play an even more important role in the battery separator film production field, becoming a key force driving industry innovation and development.