| Abstract Scope |
The pore structure of polymeric separators plays a decisive role in determining ionic conductivity, electrolyte uptake, and mechanical integrity in rechargeable batteries. In this work, the influence of water chamber immersion time during the phase inversion process on the morphology of polyetherimide (PEI)-based separators was systematically investigated. By varying immersion duration, distinct pore evolution behaviors were observed. Short immersion led to dense and poorly connected pores, moderate immersion resulted in a balanced interconnected structure with optimal electrochemical performance, while long immersion produced macro-voids and mechanical fragility. Characterization techniques such as SEM, XRD, Gurley Denso-meter were used for investigation. The results highlight that tuning immersion time is a critical parameter for optimizing PEI-based separator design. |