Celgard®

The key to the strength of Celgard’s base film is the unique dry-process manufacturing capability. This solvent-free process consists of extrusion, lamination, annealing, stretching, and slitting and results in thermally, chemically, and physically stable membranes that are designed to match customer needs.

Celgard’s machine direction (MD) only stretched base films are uniaxially-oriented in the machine direction (MD) with high strength and practically zero transverse direction (TD) shrinkage. As a battery separator, these features significantly improve cell manufacturability and safety.

Celgard’s MD + TD stretched base films are biaxially-oriented in the machine direction (MD) and transverse direction (TD) to add other unique and patented film and pore characteristics.

The proprietary trilayer film technology is a key feature that differentiates Celgard® battery separators from those manufactured by other suppliers. This unique process capability allows Celgard to combine the inherent benefits of polypropylene (PP) and polyethylene (PE) membranes into a single base film.

Celgard® Trilayer PP/PE/PP Separators are ideally suited for lithium-ion battery applications, offering:

Protection Against Thermal Events
●The PE inner layer in Celgard® Trilayer base films has a lower melt temperature (around 130°C) that provides high-speed shutdown capability.
●PP outer layers have a higher melting temperature (around 165°C) that provide high temperature stability.

Improved Stability at Higher Voltages
●The chemically stable PP outer layers of Celgard® Trilayer base films are designed to withstand the oxidizing effect of the cathode as well as the corrosive nature of electrolyte in different battery chemistries.
●Because of this oxidation resistance, Celgard® Trilayer separators maintain their structural integrity at high voltages – lowering the risk of internal shorting.
With additional benefits including compression resistance, z-direction strength, and low tortuosity, Celgard® Trilayer base films are one of the safest and most durable battery separator solutions for high power performance cells.

Celgard® Trilayer PP/PE/PP base films are available in thicknesses ranging from 10 to 38 microns.

Chemical and dimensional stability are the most critical benefits provided by Celgard® monolayer polypropylene (PP) base films in battery separator and specialty membrane applications.

Celgard® Monolayer PP separators offer oxidation resistance and are stable across a wide thermal range – making them well-suited for applications where high temperature operation may be required but shutdown features are not needed.

Celgard® Monolayer PP separators available in thicknesses ranging from 5 to 25 microns and can also be coated and/or laminated for specialty battery applications.