Wet Process Separator 20μm

Product Overview

Huizhou BestGemo New Energy presents the Wet Process Lithium Battery Separator 20μm, a polyethylene (PE) base film engineered specifically for power and energy-storage lithium battery applications. This 20-micron variant is produced using the wet process method, which yields a uniform microporous structure that balances high ionic conductivity with robust mechanical integrity. As a general-purpose base film with a thicker profile, it is designed to meet the core performance demands of modern battery cells, providing a reliable physical and electrochemical barrier between the anode and cathode while offering enhanced mechanical support for larger-format cells.

The 20μm thickness is particularly suitable for applications where additional dimensional stability and puncture resistance are desired, such as high-capacity prismatic cells and large-format energy storage systems. Its composition ensures dimensional stability under thermal stress, with controlled shrinkage in both machine direction (MD) and transverse direction (TD) at elevated temperatures. Each roll is produced under stringent process controls to deliver consistent porosity and permeability, ensuring predictable electrolyte wetting and ionic transport across the entire electrode surface.

Key Features

• High ionic conductivity enabled by a uniform porosity of 40±4%, facilitating efficient lithium-ion transport and reduced internal resistance.
• Robust mechanical strength with MD tensile strength of 1,500 to 3,000 MPa and TD tensile strength of 1,300 to 2,800 MPa, supporting high-speed winding and cell assembly without tearing, with the 20μm profile offering added structural margin.
• Controlled thermal shrinkage of ≤3% (MD) and ≤2% (TD) at 90°C, contributing to electrode alignment stability and reducing the risk of internal short circuits during thermal exposure.
• Optimized air permeability ranging from 130 to 210 sec/100cc, ensuring balanced gas exchange during formation and consistent electrolyte penetration.
• 20μm thickness with a corresponding square weight within the range of 4.2 to 10.7 g/m², enabling precise cell design tuning for high-capacity applications.
• Polyethylene wet-process base film chemistry that delivers intrinsic chemical stability against common liquid electrolytes and additives.

Technical Specifications

Applications

This 20μm wet-process separator is a dedicated solution for power lithium batteries—such as those used in electric vehicles, hybrid vehicles, and high-rate power tools—as well as for energy-storage batteries deployed in stationary grid storage, uninterruptible power supplies, and renewable energy integration systems. The thicker profile provides additional mechanical robustness, making it well-suited for large-format cells and applications where enhanced separator integrity is prioritized. Its balanced performance profile makes it suitable for cells that require reliable cycling, moderate to high discharge rates, and consistent thermal behavior.

• Electric vehicle (EV) and hybrid electric vehicle (HEV) battery cells, particularly large-format prismatic designs.
• Utility-scale and residential stationary energy storage systems.
• High-rate discharge power battery packs for industrial equipment.
• Backup power and load-leveling battery modules for commercial facilities.
• Portable power stations and solar-plus-storage configurations.

Quality Assurance

• Strict quality management is applied throughout each production stage, from raw material intake to slitting and final packaging.
• Every batch undergoes full inspection prior to shipment, including verification of thickness, porosity, permeability, tensile strength, and thermal shrinkage against stated specifications.
• Technical support is available to assist with product selection, application guidance, and troubleshooting during cell assembly trials.
• Samples are available upon request for internal evaluation and compatibility testing before volume procurement.

OEM/ODM Customization

Huizhou BestGemo New Energy offers flexible customization for the Wet Process Lithium Battery Separator 20μm to align with varying battery design requirements. Finished width can be tailored to a customer’s precise needs, whether for narrow prismatic cells or wide pouch formats. Additionally, while 20μm is the standard thickness for this variant, we can adjust square weight and air permeability within the stated ranges to meet specific performance targets. Our engineering team will work with you to specify the correct parameters based on your cell chemistry, electrode coating, and assembly equipment, ensuring the separator integrates seamlessly into your production line.