文獻名： Novel PVA-based Porous Separator Prepared via Freeze-drying for Enhancing Performance of Lithium-ion Batteries

作者：Yuanjian Xie, Yuanfeng Pan, and Pingxiong Cai

摘要：To address the challenges encountered by conventional polyolefin separator for lithium-ion batteries (LIBs) i.e., the porous polyvinyl alcohol (PVA) separator with tailored structure was developed in this work. In the preparation, submicron spindle-shaped CaCO3 acted as an excellent pore forming agent, followed by freeze-drying to create dehydrated polyvinyl alcohol (d-PVA) as novel porous separator to endow LIBs with better performace, safety in particular. The resulting d-PVA porous separator possessed high thermal dimensional stability (above 180 ℃), tensile strength (42.3 MPa), mechanical flexibility, high porosity (65.4%) and admirable electrolyte wettability. Moreover, the separators showed higher ionic conductivity (1.27 mS cm−1) than PP separator (0.4 mS cm−1). Consequently, the LiFePO4/Li half-cell with d-PVA porous separator demonstrated the better cycling performance than PP separator, even at high rate. Undoubtedly, as-prepared d-PVA porous separator is of great potential in improving performance and safety of LIBs.