Plasma-Modified Polyethylene Separator Membrane for Lithium-ion Polymer Battery

Abstract

This chapter describes the fabrication of a novel modified polyethylene (PE) membrane using plasma technology to create high-performance separator membrane for practical applications in rechargeable lithium-ion polymer battery. The surface of PE membrane as a separator for lithium-ion polymer battery was modified with acrylonitrile via plasmainduced coating technique. The plasma-induced acrylonitrile coated PE (PiAN-PE) membrane was characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and contact angle measurements. The electrochemical performance of lithium-ion polymer cell assembly fabricated with PiAN-PE membranes was also analyzed. The surface characterization demonstrates that the enhanced adhesion of PiAN-PE membrane resulted from the increased polar component of surface energy. The presence of PiAN induced onto the surface of PE membrane via plasma modification process plays a critical role in improving the wettability and electrolyte retention, the interfacial adhesion between the electrodes and the separator, and the cycle performance of the resulting lithium-ion polymer cell assembly. This plasma-modified PE membrane holds a great potential to be a promising polymer membrane as a high-performance and cost-effective separator for lithium-ion polymer battery. This chapter also suggests that the performance of lithium-ion polymer battery can be greatly enhanced by the plasma modification of commercial separators with proper functional materials for targeted application.