Lithium Battery
The application of sanitary-grade valves in lithium-ion battery production centers on addressing two critical issues: purity and safety. Battery manufacturing is extremely sensitive to metal contamination; even trace amounts of copper, zinc, or iron can lead to spontaneous combustion or performance degradation.
These valves are utilized throughout the entire production process—from slurry preparation to cell electrolyte filling—with a primary focus on the following four core stages:
1. Electrode Slurry Mixing: Strict Prevention of Metal Contamination
This is the initial step in battery production, involving the mixing of active materials, conductive agents, and binders into a homogeneous slurry. Because the slurry contains solvents and is highly sensitive to metal ions, wear-related issues in conventional pumps and valves are a significant concern.
Key Challenge: During long-term operation, moving parts in conventional stainless steel valves (such as seals in lobe pumps) can generate metal wear particles. If these particles mix into the slurry, they contaminate the electrode, potentially causing internal short circuits in the battery.
Sanitary-Grade Solutions:
Diaphragm Valves: These are the primary choice for this stage. They feature a design that completely isolates the process medium from the actuator mechanism; the absence of dynamic seals fundamentally eliminates leakage and external contamination.
Metal-Free Contact Pumps: Some manufacturers are adopting electric diaphragm pumps with non-metallic wetted parts (such as PP plastic). This completely eliminates rotating metal components, thereby ensuring slurry purity.
Copper-Free/Zinc-Free Materials: In high-precision process stages, valve body materials are subject to strict requirements; components in contact with the medium must contain less than 0.5% copper and zinc to prevent metal ion migration.
2. Slurry Transfer and Coating: Ensuring Flow Stability
Once mixed, the slurry must be transported steadily and without pulsation to the coating machine for uniform application onto copper or aluminum foil.
Key Challenge: The slurry typically has high viscosity and high solids content (e.g., ceramic slurry). Conventional pumping methods often generate pressure pulsations and air bubbles, leading to uneven coating thickness and compromising battery capacity consistency.
Sanitary-Grade Solutions:
Sanitary Ball Valves: Used for pipeline shut-off and flow control, these valves feature a fully encapsulated seat seal design that minimizes medium retention, facilitating easy cleaning and maintenance. Low-Pulsation Transfer: Modern electric diaphragm pumps utilize optimized valve designs to effectively suppress pulsation, ensuring smooth fluid transfer, preventing bubble formation, and improving coating yields.
3. Electrode Drying and Dust Removal: Precision Environmental Control
After electrode sheets are dried and slit, surface dust and impurities must be removed.
Key Challenge: Dust within the workshop or metal debris shedding from pulse dust-removal equipment itself can contaminate the electrode sheets.
Hygienic Solutions:
Low-Copper/Zinc Pulse Valves: Designed for dust removal systems. These valves strictly limit copper and zinc content in components such as the valve body and diaphragm to prevent metal debris from contaminating the air during prolonged high-frequency vibration; they meet ISO Class 4 (Class 10) cleanroom standards.
Ultra-Long Service Life: Core components offer a cycle life exceeding 1 million operations, reducing maintenance frequency and thereby lowering the risk of introducing contaminants during manual servicing.
4. Electrolyte Transfer and Filling: Absolute Sealing Integrity
Electrolytes are organic solvents that are both flammable and corrosive.
Key Challenge: Even the slightest leak can lead to battery failure or even fire.
Hygienic Solutions:
High-Sealing Valves: These require superior leak-proof ratings to ensure complete integrity during high-pressure filling processes.