Hydrophilic Surfactant Coated PP (Polypropylene, Celgard A273) Disk or Roll as Aqueous Battery Separator, CABSHSPPCA273

Celgard® A273 is a specialized, hydrophilic surface-modified microporous polypropylene (PP) monolayer separator engineered for rapid wet-out and low interfacial resistance in aqueous, alkaline, and highly polar electrolyte systems. Standard polyolefin battery membranes are inherently hydrophobic, but Celgard A273 incorporates a proprietary surfactant surface treatment across its open pore structure to enable immediate, spontaneous electrolyte absorption without requiring alcohol pre-treatment or prolonged vacuum soaking.

The core advantages of the Celgard A273 separator are: (1) Immediate Spontaneous Wetting: Drastically reduces electrolyte filling time and eliminates dry spots during assembly with high-surface-tension electrolytes (e.g., concentrated KOH, aqueous zinc salts, or ionic liquid blends). (2) Low Area-Specific Resistance (ASR): High open porosity and uniform nano-channel distribution provide low ionic transport resistance, supporting high discharge rates and low polarization. (3) Chemical & Alkaline Resilience: Retains the high chemical resistance of isotactic polypropylene against strong bases, mild acids, and oxidative decomposition at ambient to moderate temperatures. (4) Dimensional Stability (Zero TD Shrinkage): Produced via Celgard's dry-stretch process, exhibiting zero transverse shrinkage under elevated operating temperatures to prevent electrode edge exposure and internal short circuits.

References: 

1. D. Wang, et al. Polydopamine hydrophilic modification of polypropylene separator for lithium ion battery, Applied Polymer, 2014, 131, DOI:10.1002/app.40543.
2. B. Yuan, et al. A surfactant-modified composite separator for high safe lithium ion battery, J. Energy Chem., 2023, 76, 398-403.