Additives for Battery Separators
BYK supplies several additives that help to improve the production process and product properties of ceramic coated polymer (e.g. polypropylene, polyethylene) separators.
The choice and dosage of the additives depend on formulation and process parameters.
BYK’s polymeric wetting & dispersing additives result in a fine and homogeneous distribution of solid particles in liquid media and ensure the long-term stability of such systems.
Dispersing additives adsorb onto the particle surface and therefore maintain proper particle spacing through electrostatic repulsion and/or steric hindrance, thus reducing the tendency towards agglomeration. In some systems, a connection between the dispersed particles can be advantageous, e.g. to prevent sedimentation of the particles. Controlled flocculating wetting & dispersing additives can build up a 3D network in dispersions to prevent particle sedimentation. Linking particles with organic molecules may also increase the mechanical flexibility of the ceramic coating.
|Electrostatic Stabilization:||Steric Stabilization:||Controlled Flocculation:|
|Influence on the ceramic dispersion||Influence on the coating|
|Stabilization of ceramic particles||Improved homogeneity|
|Prevention of re-agglomerates of ceramic particles after dispersion process||Improved mechanical flexibility due to an interaction with the binder matrix|
|Increased solid content|
|Improved storage stability (e.g. electrostatic or steric stabilization and controlled flocculation)|
Surface wetting agent
Surface additives (e.g. silicone surfactants) improve the wetting of hydrophobic surfaces with ceramic dispersions.
In aqueous systems, the combination of a non-polar polydimethylsiloxane and a hydrophilic polyether group significantly lowers the surface tension. This improves the coating speed and adhesion of the coating.
In addition to silicone surfactants, BYK offers silicone free wetting agents that are based on alcohol alkoxylates. They reduce the dynamic surface tension and are particularly suitable for high-speed coating.
The dispersion process of ceramic particles is often accompanied by the formation and stabilization of foam. Prior to coating, defoaming of the ceramic dispersion is required to ensure a defect-free coating without pinhole formation due to encapsulated foam bubbles.
BYK supplies different types of defoamers (e.g. mineral oil defoamers, silicone defoamers, and silicone-free polymer defoamers) that help to minimize foam formation and improve the defoaming process.
Detailed information on this product group can be found in this brochure:
Technical Information L-DI1: Defoamers and air release additives
Please feel free to ask us about the appropriate products for your solution: Battery.BYK@. altana. com