In the lithium battery manufacturing industry, humidity control is a critical factor that directly affects product quality and safety. Even trace amounts of moisture can trigger violent reactions with lithium metal, leading to explosion risks, corrosion of battery components and precision equipment, destabilization of electrolytes, battery swelling, and leakage—ultimately impacting product yield and service life. Therefore, establishing an ultra-low humidity production environment has become key to breaking through technical bottlenecks in the industry.
To meet this challenge, we've developed a professional-grade desiccant rotor dehumidification system—engineered to protect the entire lithium battery production process with cutting-edge technology.
At the heart of the system is a high-performance dehumidification rotor made from imported molecular sieves and silica gel composite materials, offering exceptional moisture capturing capacity.
Humid air is drawn in by a fan and passes through the adsorption zone, where moisture is efficiently removed before the dry air is recirculated back to the workshop. Once saturated, the rotor automatically rotates into the regeneration zone, where high-temperature airflow strips away the moisture—enabling continuous 24/7 operation without interruption.
This system can stabilize the dew point temperature in production areas at ≤ -40°C, meeting the stringent humidity demands of lithium battery production. It boasts four key advantages:
·Advanced PLC control system: Real-time humidity monitoring with automatic parameter adjustments ensures stable humidity levels.
·High dehumidification efficiency: Quickly processes large air volumes, rapidly reducing humidity to the desired range.
·Reliable and stable performance: Maintains precise dehumidification even during long-term operation.
·Energy-saving design: Significantly reduces regeneration energy consumption and cuts operational costs.
Successfully deployed by leading lithium battery manufacturers—from raw material processing to cell assembly—this solution has dramatically reduced defect rates, improved production efficiency, and set a benchmark for humidity control.
Full-Process Precise Humidity Control Strategy (Customized by Process)
1.Process-specific Dew Point Adaptation:
a. For the varying needs of different stages in lithium battery production (e.g., raw material storage (positive and negative electrode materials, electrolyte): dew point ≤ -30°C to prevent material moisture absorption and failure);
b. Coating / Rolling Process: dew point ≤ -10°C to avoid moisture absorption by the electrodes, which could cause coating defects;
c. Filling / Packaging Process: dew point ≤ -50°C to prevent reaction between moisture and lithium salt, which could generate corrosive HF gases;
d. Winding / Assembly Workshop: dew point ≤ -20°C, combined with temperature and humidity linkage control, ensuring stable battery performance. The equipment supports independent humidity control in multiple areas and allows the PLC system to preset different humidity curves for each process, meeting the precise needs of the entire production process.
2.Cleanroom Compatibility:
As a core cleanroom component, the dehumidifier uses food-grade stainless steel (e.g., 316L) with electrolytic-polished interiors (Ra ≤ 0.8μm) to minimize particle retention. Standard G4 + F9 + H13 (customizable to H14) three-stage filtration ensures ISO Class 5 (Class 100) air cleanliness during dehumidification, seamlessly integrating with cleanroom designs and eliminating secondary contamination.
Extreme Environment Adaptability & Enhanced Safety Design
1.Explosion-Proof & Anti-Static Design:
To address the potential hydrogen leak risks in lithium battery workshops, the motors and electrical control systems are equipped with Ex d IIC T4 certified explosion-proof components. Additionally, the internal air channels are coated with an anti-static layer (surface resistivity ≤ 10⁶Ω), preventing static electricity buildup and spark generation.
Hydrogen gas concentration linkage: if sensors detect ≥1% LEL, the system switches to safe mode (lower regeneration temp, increased fresh air), with alarm triggers.
2.Corrosion Resistance:
To combat the corrosion caused by HF gas from electrolyte vapor, the rotor frame is made of anodized aluminum alloy with a PTFE (polytetrafluoroethylene) coating. The core adsorption material is specially treated to be acid-resistant, which increases its lifespan by 30% compared to conventional rotors, making it suitable for long-term operation in highly corrosive environments.
Modular Lithium Battery Cleanroom with Ultra-Low Dew Point
▶Coordinated Optimization of Modular Architecture and Ultra-Low Dew Point Control
1. Fully Prefabricated Modular Integration
Modular Dew Point Control Unit:
The system integrates the desiccant rotor, filtration system, fan assembly, and regeneration heat source (such as waste heat exchanger or electric heater) into a standardized container-type module (available in 20-foot or 40-foot options, stackable and combinable). All piping, wiring, and control systems are pre-installed at the factory, requiring only fast on-site assembly. Compared with traditional construction, installation time is reduced by 60% (from the usual 30 days to 12 days with modular deployment).
Enhanced Moisture Resistance of Cleanroom Partitions:
Wall modules are built with double-layer laminated tempered glass or double-layer rock wool sandwich panels (core density ≥120 kg/m³, thermal conductivity ≤0.04 W/m·K). The interior surface is clad with 0.3 mm thick food-grade stainless steel (electropolished), and all seams are sealed with silicone rubber gaskets (temperature resistance from -40°C to +80°C, water absorption ≤0.1%). The air leakage rate is ≤0.5 m³/(㎡·h), effectively preventing external moisture ingress.
2. Flexible Expansion and Zonal Humidity Control
Parallel / Series Module Configurations:
To accommodate phased construction in lithium battery plants, the system supports “plug-and-play” modular expansion (e.g., Phase 1: 1000㎡; Phase 2: add 500㎡ module, integrated within 3 days). Each module can be individually configured for a specific dew point (ranging from -20°C to -60°C), and the central PLC system enables cross-module humidity balancing and scheduling.
Case Study: A battery factory deployed three -50°C modules in electrolyte filling and two -30°C modules in formation. Linked by differential pressure sensors and air valves, the system prevents moisture backflow and cuts energy use by 25%.
▶II. Core Technology Upgrades for Ultra-Low Dew Point in Modular Cleanroom
1. High-Efficiency, Compact Dew Point Control Components
Miniaturized Rotor Technology:
Uses high-capacity honeycomb desiccant rotors (30% smaller in volume compared to conventional rotors, moisture adsorption ≥1.2g H₂O/kg dry air), tailored for compact modular integration. A single module handles 5,000–20,000 m³/h airflow with dew point stability within ±1.5°C Td.
Integrated Deep Drying Unit:
Equipped with a membrane-based deep dehumidification unit at the module outlet, using selective permeation membranes to remove water vapor molecules as small as 0.01μm. Designed for extreme environments such as solid-state battery electrolyte production, this unit achieves dew points as low as ≤ -70°C (at atmospheric pressure), with pressure drop ≤150Pa—eliminating the need for complex multi-stage piping systems in traditional setups.
2. Optimized Modular Airflow Organization
CFD-Based Pre-Design:
Each module undergoes computational fluid dynamics (CFD) simulation before delivery to optimize airflow paths, ensuring supply air angles ≤30° to prevent turbulence near the cleanroom ceiling.
Moisture-Resistant Return Air Filtration:
Return vents are equipped with moisture-resistant filters (filtration ≥5μm) and form a closed-loop "supply–return–treatment" cycle with the intake of the dehumidification module. This design reduces humidity response time to just 10 minutes (vs. ≥30 minutes in traditional systems).
Modular Pressure Gradient Control:
Pressure sensors (accuracy ±0.1Pa) work in coordination with motorized dampers to maintain a positive pressure gradient across functional zones—from the raw material area (0 Pa) → electrolyte filling area (+10 Pa) → packaging area (+20 Pa). This setup effectively blocks reverse infiltration of external moisture and particulates.
▶III. Enhanced Safety and Reliability of Modular Systems
1. Explosion-Proof Modular Design
Independent Explosion-Proof Units:
For high-risk processes such as electrolyte filling and baking, each module is equipped with explosion-proof dehumidifiers (motors and control boxes certified to Ex IIB T4 standards).
Modules feature ESD grounding copper strips (ground resistance ≤ 4Ω) and are integrated with the plant-wide explosion protection system.
In case a single module detects elevated hydrogen concentration, it automatically isolates itself while keeping other zones in safe operation.
Quick Maintenance Module Design:
Key components such as dehumidification rotors and filters are designed with a drawer-type quick-disassembly structure, allowing for part replacement within 15 minutes without system shutdown (traditional setups require a 4-hour downtime). Pre-assembled backup modules ensure "zero downtime" maintenance.
2.Moisture and Corrosion-Resistant Material System
Module Surface Treatment:
Exposed metal parts are coated with powder electrostatic spray (epoxy resin coating, thickness ≥80μm), with salt spray resistance ≥1000 hours. The interior of the ducts is lined with Teflon (PTFE) to resist corrosion from HF gas emitted by electrolyte evaporation (lifetime ≥5 years at concentrations ≤50ppm).
Weather Resistance of Sealant:
All module seams are sealed with perfluoroether rubber (FFKM) seals, which can withstand temperatures from -20°C to +200°C and are three times more resistant to chemical corrosion than conventional silicone rubber, preventing air leakage caused by the hardening and cracking of seals in low dew point environments.
▶IV. Intelligent Modules and Digital Delivery
1. Modular IoT Integration and Remote Operation & Maintenance
Module-Level Digital Twin:
Each cleanroom module is equipped with a 16-channel sensor matrix (monitoring dew point, temperature, humidity, differential pressure, energy consumption, and filter pressure drop). Data is uploaded to the cloud platform via 5G/Wi-Fi, generating real-time health reports for each module (e.g., alerts for desiccant wheel adsorption efficiency degradation and seal wear prediction). This system enhances operational efficiency by 40%.
Remote Parameter Configuration:
Supports remote operation via mobile apps or PC, allowing independent configuration of each module's operational settings (e.g., nighttime energy-saving mode: relaxing dew point target to -35°C, reducing energy consumption by 40%). Settings are automatically synchronized with the central control system, adaptable to multi-shift production schedules.
2.Modular Delivery Standards and Certification
Factory Pre-Verification
Each module undergoes a 72-hour full-load dew point stability test (dew point fluctuation ≤ ±2°C Td) and a cleanliness self-test (ISO 5 standard, ≥0.5μm particle count ≤ 3520 per m³) in the factory. A 3D scan completion diagram and CM verification report are provided with each module, significantly shortening on-site commissioning time.
Industry Compliance and Adaptation
The modular solution complies with GB 50073-2013 “Cleanroom Design Standards,” GB/T 25915.1-2021 “Cleanrooms and Associated Controlled Environments,” and can be certified according to international standards like FDA and EU GMP, based on customer requirements.
