Abstract: The polysiloxane/polyphenylene sulfide (PVS/PPS) nonwoven composite separator was first fabricated by employing polyvinylsilsesquioxane (PVS) polymer as the coating material and PPS nonwoven as the substrate. The physical properties, electrochemical behavior and battery performance of the separator were systematically investigated. Compared with polyolefin separator (PP/PE/PP), the PVS/PPS composite separator is discovered to display highly developed microporous structure, superior electrolyte wettability, higher ionic conductivity and enhanced compatibility with electrode. These behaviors can be helpful for weaken ohmic polarization degree in case of charging/discharging, which finally endows battery with higher discharge specific capacity and outstanding cyclic stability (retention rate is ahout 100%). The PVS/PPS composite separator can exhibit excellent heat resistance and dimensional stability even after thermal treatment at 250℃ for 1 h. Accordingly, there is a promising prospect for PPS nonwoven-based composite separator in the development of the high power lithium ion battery.