Analysis of Core Application Scenarios of Compressed Air in Lithium Battery Production
in the field of lithium battery manufacturing, compressed air, as a key auxiliary medium, runs through the core process links such as electrode preparation, cell assembly, chemical packaging and testing and packaging, which plays an irreplaceable role in ensuring product quality, improving production efficiency and maintaining equipment stability. The following from a professional point of view, combined with the industry general process, the system describes the core application of compressed air in the production of lithium batteries.
1. electrode preparation process: the key support for precision coating and drying
- pole piece coating
- environmental Control during the coating process of positive and negative electrode slurry, compressed air forms vertical and unidirectional air flow through FFU (fan filter unit) to maintain the cleanliness of the workshop at ISO level 6 (100) standard and prevent dust adhesion from causing coating defects.
- Equipment cleaning: Use 0.4-0.6MPa compressed air to pulse back blow the coating die, and clean the residual slurry every 2 hours to avoid poor streaks caused by die blockage.
- Pole piece drying
- airflow distribution in the oven, the compressed air is guided to the surface of the pole piece in the form of laminar flow through the specially designed nozzle array, realizing the precise control of temperature uniformity of 1 ℃ and preventing the bulge or wrinkle caused by solvent residue.
2. cell assembly process: the guarantee of high-precision manufacturing
- winding/Laminating
- tension control: In the process of winding or laminating the pole piece, the pneumatic brake provides a constant tension of 0.1-0.3MPa to ensure that the flatness of the pole piece is ≤ 0.1mm and avoid the risk of diaphragm puncture.
- dust removal and purification: An ion air knife is set near the winding head, and compressed air is used to generate static electricity to eliminate airflow, and the number of particles is controlled within 100/m & sup3; to prevent hidden dangers of short circuit.
- package welding
- pneumatic clamp: The packaging mold driven by a double-acting cylinder is adopted to provide a clamping force of 0.5-0.7MPa to ensure the width tolerance of the aluminum-plastic film packaging edge is ± 0.1mm to prevent electrolyte leakage.
- Laser protection A positive pressure air curtain of 0.2MPa is formed in the laser welding area to isolate the optical lens from the pollution of welding fumes and extend the equipment maintenance period.
3. injection and formation processes: shaping electrochemical performance
- electrolyte injection
- quantitative perfusion: The precise perfusion of electrolyte 0.1-1.0 mL/s is realized by pneumatic diaphragm pump, and the negative pressure environment of vacuum cavity-0.09MPa is matched to ensure the tolerance of liquid injection volume ≤ 1%.
- bubble elimination: An ultrasonic vibration device is set up at the liquid injection port, supplemented by 0.3MPa compressed air purging, to control the bubble content in the electrolyte below 0.5, and to improve the consistency of the battery cell.
- Activation
- pressure loading: In the formation fixture, a constant pressure of 1-5MPa is applied through the gas-liquid booster cylinder to ensure the close contact between the pole piece and the diaphragm and reduce the contact resistance.
- temperature regulation the vortex refrigerator is driven by compressed air, and the ambient temperature of the formation is controlled within the range of 45±2 ℃ to optimize the quality of SEI film formation.
4. inspection and packaging process: the last line of defense for quality control
- air tightness detection
- differential pressure detection: Charge 0.4MPa compressed air into the inner cavity of the battery core, and monitor the pressure drop value within 10 seconds through a high-precision pressure sensor to determine whether the leakage rate is ≤ 0.1/min.
- Helium Mass Spectrometry Leak Detection: For high safety requirements, the use of compressed air carrying helium as a tracer gas, the detection sensitivity of up to 1 x 10, Pa-m & sup3;/s.
- Automated Packaging
- robot grasping: The adsorption force of-0.08MPa is generated by the vacuum generator, and the precise positioning of the battery core is realized with the pneumatic sliding table. The vacuum breaking time is ≤ 0.3 seconds, thus avoiding the deformation of the battery core.
- Laser coding: Use compressed air to cool the laser lens to ensure the clarity of the coding depth of 0.1-0.3mm and meet the traceability requirements.
5. environment and equipment maintenance: guarantee of continuous operation
- dust-free environment maintenance
- positive pressure hold: Maintain a positive pressure environment of 5-10Pa in the drying room, and realize air replacement 30-50 times per hour through FFU driven by compressed air to ensure that the dew point temperature is ≤-40 ℃.
- Preventive maintenance of equipment
- automatic lubrication: In key equipment such as laminating machines and winding machines, a single-point lubricator driven by compressed air can quantitatively supply 0.1mL of grease every 8 hours to extend the life of the equipment.
Conclusion
compressed air plays the role of "invisible assistant" in the production of lithium batteries, and its application runs through the whole process from pole piece preparation to finished product packaging. By providing a clean power source, achieving precise control and ensuring environmental stability, compressed air technology has become a key element in improving lithium battery product quality, production efficiency and equipment reliability. Enterprises need to combine specific process requirements, build a compressed air supply system in line with ISO 8573-1 standards, and supporting intelligent monitoring and maintenance system, in order to continuously optimize the manufacturing process, to meet the power battery industry for high quality, high efficiency, high safety requirements.
