静电纺丝与静电喷雾技术共纺制备PPESK/PVDF复合锂电池隔膜

为了改善传统静电纺丝无纺布纤维膜力学性能较差的缺点,采用静电纺丝和静电喷雾技术相结合的方法,同时进行静电纺PPESK浓溶液和PVDF稀溶液,制备得到PPESK纤维/PVDF珠粒复合锂电池隔膜,并在160℃进行热压后处理。通过扫描电子显微镜、万能拉伸试验机、电化学工作站及充放电测试仪等表征复合锂电池隔膜的微观结构、力学性能、离子电导率和相应的电池充放电性能。结果表明,该复合隔膜具有良好的电解液润湿性,室温下离子电导率达到1.92mS·cm^-1,PVDF珠粒均匀地分布在PPESK纤维中,珠粒经热压产生微熔融有效增强了纤维之间的黏结力,使复合膜的力学强度提高到13.2MPa。此外,使用复合隔膜装配的电池展现出较高的放电比容量和稳定的循环性能。

PPESK/PVDF Lithium-ion Battery Composite Separators Fabricated by Combination of Electrospinning and Electrospraying Techniques

In order to improve the mechanical property of traditional electrospinning fibrous membranes,PPESK-fiber/PVDF-bead composite membranes were prepared via simultaneously electrospinning of PPESK concentrated solution and electrospraying of PVDF dilute solution,and then hot pressed at 160C.The membrane structure,tensile strength,ionic conductivity and cycling performance of lithium-ion batteries were measured by scanning electron microscope,universal tensile test machine,electrochemical work station and battery cycle system.The results show that the hotpressed PPESK/PVDF composite membrane separator exhibits excellent liquid electrolyte wettability,ionic conductivity reaches 1.92mS · cm-1 at room temperature,PVDF beads are uniformly dispersed in PPESK fibers.The interfacial strength of PPESK fibers is effectively enhanced due to the melt of PVDF beads during the hot press process,hence the mechanical strength of composite membrane is leached 13.2MPa.In addition,cells assembled with PPESK/PVDF composite membrane show high discharge capacity and stable cycling performances.