The PSA nitrogen generator system for lithium battery industry adopts pressure swing adsorption as the core technology to produce high-purity nitrogen on-site, widely used in lithium battery processes including electrode coating, calendering, winding, liquid injection, formation, sealing and cell warehouse storage. Lithium battery production is highly sensitive to water vapor and oxygen. Cells exposed to oxygen compounds and high-humidity environments are prone to side reactions, resulting in capacity fading, bulging and even thermal runaway risks. The lithium battery PSA nitrogen generator system is not a standalone nitrogen generation host, but an integrated complete system composed of a pretreatment unit, PSA nitrogen adsorption host, buffer and pressure stabilization unit, online monitoring unit, control interlock unit and exhaust emission unit. All modules operate cooperatively to continuously supply low-oxygen high-purity protective nitrogen to lithium battery workshops. From air source purification, adsorption separation, pressure-stabilized delivery and online monitoring to safety interlocking, it builds a complete inert gas supply system to guarantee process stability and operational safety of lithium battery production lines.

　　The air pretreatment subsystem serves as the first barrier of the whole lithium battery PSA nitrogen generator system and directly protects the downstream carbon molecular sieve adsorption medium. Water, oil mist and solid dust contained in compressed air are major contaminants that degrade molecular sieve performance. The pretreatment subsystem generally includes a refrigerated dryer, multi-stage precision filters, activated carbon oil removal filters and drainage assemblies. Compressed air output from the air compressor first enters the refrigerated dryer to reduce the dew point of compressed air and remove most free water. It then passes through precision filters of different accuracy grades to filter solid particles and liquid oil droplets step by step. Activated carbon filters deeply adsorb residual oil mist. Humidity inside lithium battery workshops fluctuates greatly, so the pretreatment subsystem must steadily reduce the dew point of inlet air and keep compressed air quality within design specifications of the system. Once the pretreatment unit fails, water vapor and oil contamination will flow directly into adsorption towers, contaminating carbon molecular sieve and causing irreversible degradation of adsorption capacity and shortening the service life of molecular sieve. Differential pressure gauges are equipped in the pretreatment system to monitor filter clogging status in real time. An early warning will trigger when differential pressure exceeds limits, reminding maintenance staff to replace filter elements promptly and prevent pollutants from breaking through into the downstream nitrogen generation host.

　　The PSA adsorption nitrogen generation host subsystem is the core unit of the gas supply system. It completes nitrogen-oxygen separation relying on the selective adsorption characteristics of carbon molecular sieve. Inside the host are two groups of adsorption towers filled with carbon molecular sieve adsorbent. Under pressurized conditions, oxygen in air is adsorbed by molecular sieve while nitrogen is enriched and exported. After adsorption saturation, the tower depressurizes for regeneration to desorb adsorbed oxygen and complete cyclic regeneration. The two adsorption towers alternately perform adsorption and regeneration to realize continuous nitrogen output. To meet lithium battery process requirements, the system adopts high-quality carbon molecular sieve to maintain stable nitrogen purity under long-duration continuous working conditions. The host is equipped with pneumatic valves, solenoid valves, silencers and pressure sensors for adsorption towers. Valves switch automatically according to preset time sequences to control the full cycle of pressurization, adsorption, pressure relief and regeneration. Internal pressure and temperature of the host are collected in real time and transmitted to the central control system. Lithium battery production lines impose strict requirements on nitrogen purity stability. Switching timing and operating pressure of adsorption towers directly affect nitrogen purity. The control system dynamically fine-tunes operating parameters according to load fluctuations to stabilize nitrogen indicators and avoid purity fluctuations interfering with cell manufacturing.

　　The buffer and pressure-stabilized delivery subsystem undertakes nitrogen storage, pressure stabilization and distribution functions to ensure stable nitrogen pressure delivered to lithium battery process equipment. This subsystem consists of nitrogen buffer tanks, pressure regulating valves, pressure transmitters, check valves, branch shut-off valves and pipe networks. Nitrogen produced from the adsorption host first flows into buffer tanks, which buffer pressure pulsation and reduce pressure fluctuations caused by alternate switching of adsorption towers. Pressure regulating valves stabilize nitrogen pressure to the process pressure required by lithium battery production lines. Lithium battery workshops contain multiple production lines with different gas pressure and flow requirements at different stations. The pressure-stabilized delivery subsystem distributes nitrogen via branch pipelines to coaters, winding machines, liquid injection cabinets and sealing equipment. Pressure monitoring points are installed on pipelines to monitor pipe network pressure in real time. Alarms will activate when pressure becomes excessively high or low. The whole delivery pipeline network adopts clean pipelines with clean inner walls free of oil contamination to prevent pipeline impurities entering cell stations and contaminating products. Branch isolation valves are installed on pipelines. When one production line needs maintenance, its gas supply can be cut off separately without affecting nitrogen supply for other lines, improving operational flexibility of the gas supply system.

　　The online monitoring and analysis subsystem monitors nitrogen quality and system operating status in real time and acts as the perception module to guarantee gas supply quality. This subsystem is equipped with online oxygen analyzers, dew point detectors, flow sensors and pressure sensors. The oxygen analyzer continuously detects oxygen concentration inside produced nitrogen, the most critical monitoring indicator for lithium battery production. Excessive oxygen content in nitrogen means failure of protective atmosphere, which directly causes cell quality defects. Dew point meters monitor water content in nitrogen and control water vapor indicators to prevent high water vapor entering process chambers and inducing cell side reactions. All monitoring data is uploaded in real time to the central control unit of the system and displayed visually on the human-machine interface. Multi-level alarm thresholds are set in the system. Level-1 early warnings indicate minor deviations and remind maintenance personnel for inspection; level-2 high alarms trigger audible and visual alerts and activate interlock protection actions when necessary. Monitoring instruments must be calibrated regularly to prevent data distortion caused by sensor drift, as false or missed alarms may bring quality risks to lithium battery production. Monitoring data is automatically stored to form production logs for process traceability, system audit and fault review.

　　The automatic control and safety interlock subsystem acts as the brain of the lithium battery PSA nitrogen generator system and coordinates all units for coordinated operation. Centered on a PLC with a human-machine touchscreen, the control system collects all signals from pretreatment, adsorption host, buffer pipe network and monitoring instruments, and automatically controls valve timing, equipment startup/shutdown and alarm management. Operators can view real-time operating parameters, historical curves and alarm records on the touchscreen and switch equipment operating modes manually or automatically. Safety interlock logic is the most important function of this subsystem with multiple protection logics: low inlet pressure triggers early warning to prevent gas supply interruption caused by air compressor failure; excessive oxygen content in nitrogen triggers interlock alarm and cuts off delivery of unqualified nitrogen to production lines when needed; system overpressure triggers interlock pressure relief to protect storage tanks and adsorption towers. Meanwhile, an emergency signal interface is integrated to connect with the central control system of lithium battery workshops for remote monitoring and remote shutdown. When abnormal working conditions occur, the system automatically executes preset protective actions to reduce risks brought by delayed manual response. The control system adopts hierarchical authority management. Different maintenance personnel are assigned corresponding operation permissions to prevent unauthorized personnel from modifying system parameters arbitrarily and ensure safe system operation.

　　The tail gas emission and noise reduction subsystem handles oxygen-rich tail gas discharged during regeneration, controls noise and optimizes workshop operating environments. Oxygen-rich air released during adsorption tower regeneration is discharged centrally through silencers and exhaust pipelines. Silencers greatly reduce airflow noise generated by valve pressure relief and gas exhaust to meet noise control standards of lithium battery workshops. Exhaust pipelines are arranged away from densely manned operation zones. Oxygen-rich air is directly discharged to outdoor atmosphere and will not accumulate inside workshops. Lithium battery workshops contain large amounts of organic solvents; oxygen-enriched environments raise combustion risks for flammable solvent vapors. The design of tail gas pipelines fully considers wind direction and diffusion conditions to prevent exhaust gas backflow into workshops. Maintenance ports are installed on exhaust pipelines to facilitate regular cleaning of dust and impurities inside pipes. No toxic or hazardous substances are discharged from the whole emission system. This physical separation process generates no waste liquid or chemical pollutants. Auxiliary noise monitoring points continuously monitor noise at discharge outlets to ensure workshop working environments meet occupational health standards.

　　The operation, maintenance and closed-loop management module guarantees long-term stable operation of the whole nitrogen generation system. The system has built-in maintenance reminder functions that automatically push maintenance alerts according to equipment running time, filter differential pressure and molecular sieve operating duration. Maintenance staff carry out regular inspections to verify instrument, valve and pipeline status of each subsystem, replace filter elements periodically and check molecular sieve performance. Energy isolation, pressure relief and lockout-tagout procedures are implemented during maintenance operations to guarantee overhaul safety. Maintenance records are entered into the system database to build a full-lifecycle maintenance archive. The system has built-in fault diagnosis functions. When valve abnormality, loss of instrument signals or abnormal pressure occurs, it automatically locates fault positions to help maintenance personnel troubleshoot rapidly. Nitrogen generation systems in lithium battery factories often adopt a parallel multi-unit structure. Multiple nitrogen generators serve as mutual backups. When one unit shuts down due to faults, the standby unit automatically starts to guarantee uninterrupted gas supply for production lines and avoid production line stoppage and cell scrap caused by gas source interruption.

　　To sum up, the PSA nitrogen generator system for lithium batteries is a complete industrial gas supply system with multi-unit coordination, online monitoring and safety interlock capabilities. From air pretreatment, PSA nitrogen adsorption host, buffer delivery, online monitoring and PLC interlock control to tail gas emission, all subsystems cooperate closely and none is dispensable. Lithium battery manufacturing is extremely sensitive to oxygen and water. This system continuously supplies low-oxygen, low-dew-point high-purity nitrogen to provide inert protective atmosphere for key processes such as coating, winding, liquid injection and sealing. The system can not only steadily guarantee the quality of process gas, but also identify hidden faults in advance through multi-stage monitoring and interlock protection, reducing production risks such as batch cell defects and thermal runaway. Constructing a complete PSA nitrogen generator system together with standardized maintenance schemes in lithium battery factories can continuously and stably supply protective nitrogen, replace purchased high-pressure nitrogen cylinders, lower safety risks and overall costs from cylinder transportation and replacement, and support long-term stable and safe production of lithium battery lines.