Unite Precision Filter: Successful Application in THF Alkaline Conditions of Lithium Battery Industry

Project Background:

Tetrahydrofuran (THF) is widely used as an excellent organic solvent in the production of lithium-ion battery electrolytes, anode materials, or related solvent recovery processes. However, in specific synthesis or cleaning stages, THF solvents often operate under strong alkaline conditions (e.g., containing lithium bases or hydroxides). These complex conditions place extremely high demands on the chemical compatibility, sealing reliability, and filtration precision of the equipment. A well-known lithium battery auxiliary enterprise in Shandong introduced Unite's high-precision filtration system to enhance material purity and ensure solvent recycling.

Core Challenges:

• Chemical Stability Tests: THF is highly permeable and, under alkaline conditions, has strong corrosive and swelling effects on ordinary seals and metallic materials.
• Explosion-Proof & Sealing Requirements: As a flammable and explosive Class A solvent, the filtration system must possess exceptional sealing performance to prevent solvent leakage and be equipped with an explosion-proof control system.
• Trace Impurity Interception: Lithium battery materials demand ultra-high purity, requiring the stable interception of micron or even sub-micron fine particles while ensuring high flow rates.

Our Solution:

Addressing the THF alkaline conditions in the lithium battery industry, Unite provided a modular precision filtration system:

• Special Materials & Sealing: The main body of the equipment is made of specially treated SS316L or high-performance alloys. Seals are made of Perfluoroelastomer (FFKM) or modified PTFE, ensuring long-term operation under the dual corrosive environment of "solvent+strong alkali."
• High-Precision Filter Elements: Equipped with Unite's independently developed high-precision metal composite filter elements or high-flux membrane elements, the system accurately intercepts fine suspended solids to ensure the clarity of the THF filtrate.
• Hermetic Explosion-Proof Design: The system utilizes a nitrogen-protected closed-loop design, equipped with explosion-proof motors and intrinsically safe instruments, eliminating safety hazards from physical structure to electrical control.
• Intelligent Monitoring System: Differential pressure transmitters monitor filter element status in real-time, supporting automatic alarms and switchovers, reducing manual intervention, and enhancing the automation level of the production line.

Customer Value & Results:

Since the commissioning of the precision filtration system at the client's site, its performance has been extremely stable. The purity of the filtered THF solvent increased by over 30%, significantly improving the qualification rate of downstream lithium battery products. The fully enclosed design drastically reduced on-site VOC emissions and improved the workshop environment. Furthermore, thanks to the excellent corrosion-resistant design, the service life of the filter elements was extended by more than 50%, saving the client significant consumable replacement costs. The successful application of this case once again demonstrates Unite's professional expertise in solving complex chemical working condition challenges in the new energy industry.