Microporous PP Lithium Battery Separator Film 16 20 25 40μm for Cell Assembly

Product Overview

This high-purity polypropylene (PP) microporous separator series provides critical electrical insulation and uniform ion transport for advanced energy storage systems. Designed for lithium-ion battery research, pilot lines, and industrial cell production, the membrane establishes a robust physical barrier between positive and negative electrodes while maintaining an interconnected sub-micron pore architecture. Available in standardized thicknesses of 16 μm, 20 μm, 25 μm, and 40 μm, this substrate enables engineers to precisely balance energy density, internal impedance, and mechanical safety.

The separator film is extensively utilized across cylindrical, prismatic, and pouch cell formats for consumer electronics, electric vehicles, stationary grid storage, and specialized solid-state/liquid hybrid battery systems. Its controlled pore network facilitates rapid electrolyte wetting and homogeneous lithium-ion flux, effectively suppressing local current concentrations and dendrite proliferation during high-rate charge and discharge cycles.

Manufactured under stringent cleanroom quality controls, this membrane demonstrates outstanding chemical inertia against aggressive non-aqueous liquid electrolytes, superior machine-direction and transverse-direction tensile strength, and minimal high-temperature thermal shrinkage. Researchers and battery manufacturers can rely on this material to maintain structural integrity under high winding tension, automated stacking pressures, and elevated thermal operating regimes.

Key Features

• Controlled Microporous Architecture: Engineered with a homogeneous sub-micron pore network achieving 35% to 50% porosity, delivering low internal resistance (Gurley air permeability tailored from 190 to 800 s/100mL) for enhanced rate capability and cycle life.
• High Mechanical Tensile Strength: Exhibits exceptional machine direction (MD) tensile strength (≥100 MPa / ≥1400 kgf/cm²) and balanced transverse direction (TD) strength to withstand high-speed automated winding and continuous winding tension without stretching or necking.
• Exceptional Puncture Resistance: Features reinforced mechanical puncture thresholds (ranging from ≥2.2 N up to ≥5.0 N / ≥400 g), providing dependable resistance against rough electrode active material surfaces, metallic burrs, and lithium dendrite penetration.
• Low Thermal Shrinkage: Demonstrates superior dimensional stability under thermal stress (MD shrinkage ≤1.5% at 90°C/1h and ≤3.0% at 115°C/16h), preventing edge retraction and internal short circuits during thermal excursions.
• Broad Electrolyte Compatibility: Formulated from chemically inert polypropylene resin that resists oxidation and reduction across wide electrochemical operating windows (0.0 V to 4.5 V vs. Li/Li⁺) and maintains dimensional stability in standard carbonate solvents.
• Uniform Areal Weight Distribution: Tightly toleranced areal density (from 6 g/m² up to 13.2 g/m²) ensures uniform membrane thickness across full master rolls, guaranteeing consistent cell-to-cell impedance and capacity matching.
• Optimized Surface Wettability: The microporous surface structure promotes rapid and complete absorption of liquid electrolytes, accelerating cell formation processes and reducing electrolyte filling cycle times.
• Customizable Roll Configurations: Standard width and roll length formats can be slit to customer-defined specifications, ensuring seamless compatibility with manual lab winding fixtures and automated industrial cell assembly machines.

Applications

Technical Specifications

Why Choose This Product

• Engineered Microstructure Consistency: High-precision dry/wet stretching manufacturing ensures tight pore size distribution and uniform permeability across every square meter, eliminating hot spots and irregular current densities.
• Superior Yield in Automated Assembly: Outstanding mechanical tensile modulus in the machine direction prevents stretching, edge curling, and wrinkling during high-speed winding and precision z-folding operations.
• Robust Safety Margin: Exceptional puncture resistance combined with strict thermal dimensional stability prevents catastrophic internal shorts caused by particle shedding, burrs, or local overheating.
• Flexible Slitting & Customization: Available in standard master rolls or custom-slit widths tailored to specific benchtop winding apparatus, pilot lines, or industrial cell assembly equipment.
• Comprehensive Battery Ecosystem Support: Backed by extensive technical expertise across the complete battery manufacturing workflow, providing seamless material-equipment integration from electrode processing to cell testing.

Contact our technical engineering team today to request custom slitting dimensions, detailed batch data sheets, or quotation packages for your laboratory and production requirements.

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