Preparation and performance of bicomponent polyacrylonitrile/polymethyl methacrylate lithium-ion battery separator by centrifugal spinning

Bicomponent polyacrylonitrile/polymethyl methacrylate (PAN/PMMA) nanofiber membrane was successfully prepared through centrifugal spinning for enhancing lithium-ion battery (LIB) separators. This study examined how varying PMMA levels influence the electrochemical and overall battery performance of PAN-based composite membranes. The PAN/PMMA (7:3) composite nanofiber separator exhibited a uniform three-dimensional network structure, alongside remarkable thermal stability. Compared with the commercial Celgard and pure PAN separators, the PAN/PMMA (7:3) nanocomposite membrane demonstrated superiority in porosity (89.28%), liquid absorption (475%), and hydrophobicity (23.5°). Similarly, the PAN/PMMA (7:3) separator demonstrated outstanding electrochemical performance, including high ionic conductivity (3.58 mS/cm), electrochemical oxidation limit (5.15 V), and low interfacial resistance (80 Ω). The battery equipped with this composite separator exhibited outstanding performance, with the initial capacity of the PAN/PMMA (7:3) separator reaching 160.5 mA h/g, maintaining 96.3% of it after 50 charge-discharge cycles. Thus, bicomponent PAN/PMMA nanofiber membranes prepared by centrifugal spinning show potential as high-performance separators for LIBs.