Centrifugal spinning is a fast, cost-effective and safe alternative to the electrospinning technique, which is commonly used for making fiber-based separator membranes. In this work, SiO2/polyacrylonitrile (PAN) membranes were produced by using centrifugal spinning and they were characterized by using different electrochemical techniques for use as separators in Li-ion batteries. SiO2/PAN membranes exhibited good wettability and high ionic conductivity due to their highly porous fibrous structure. Compared with commercial microporous polyolefin membranes, SiO2/PAN membranes had larger liquid electrolyte uptake, higher electrochemical oxidation limit, and lower interfacial resistance with lithium. SiO2/PAN membrane separators were assembled into lithium/lithium iron phosphate cells and these cells delivered high capacities and exhibited good cycling performance at room temperature. In addition, cells using SiO2/PAN membranes showed superior C-rate performance compared to those using microporous PP membrane.