This paper reports an eco-friendly approach for extracting cellulose acetate (CA) from waste cigarette filter to construct a cellulose-based membrane separator for a high-performance lithium-ion battery. A cellulose/poly(vinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) nanofiber membrane was prepared by coaxial electrospinning of a cellulose acetate core and PVDF-HFP shell, then hydrolyzed by LiOH. The cellulose-core/PVD-HFP-shell fibrous membrane shows good tensile strength (34.1 MPa), high porosity (66%), excellent thermal stability (to 200 degrees C), and super electrolyte compatibility (355% electrolyte uptake). It has a lower interfacial resistance (98.5 Omega) and higher ionic conductivity (6.16 mS cm(-1)) than those of commercial separators (280.0 Omega and 0.88 mS cm(-1)). In addition, the rate capability (138 mAh.g(-1)) and cycling performance (75.4% after 100 cycles) are also superior to those of the commercial separators, demonstrating the cellulose-core fibrous membrane to be a promising separator for a high-power and more secure lithium-ion battery.