静电纺丝三明治结构纤维膜的可控制备及其电化学性能

Preparation and Electrochemical Properties of A Sandwich Structure Fibrous Membranes by Electrospun

利用静电纺丝法制备聚偏氟乙烯/聚对苯二甲酸乙二醇酯/聚偏氟乙烯(PVDF/PET/PVDF)三明治结构纤维膜,对纺丝膜进行形貌表征、力学性能测试、差示扫描量热分析(DSC)、热失重分析(TG),研究纤维膜结构对其综合性能的影响。结果表明:5层三明治结构纺丝膜的拉伸强度为1.64 MPa,且具有优异的热稳定性,起始分解温度达445℃。将不同结构的纺丝膜在电解液中活化并组装成锂离子二次电池,研究其电化学性能。5层纺丝膜(PETPVDF-5)的吸液率达2 818%,显著高于单PVDF纺丝膜。PET-PVDF-5在组装成锂离子二次电池后具有较高的离子电导率(2.16 mS/cm)、较宽的电化学稳定窗口(4.85 V)以及稳定的循环充放电性能。

The poly(vinylidene fluoride)/polyethylene terephthalate/poly(vinylidene fluoride)(PVDF/PET/PVDF)sandwich structure fibrous membranes were prepared by electrostatic spinning. The morphological characterization,mechanical properties test, differential scanning calorimetry(DSC) analysis and thermogravimetric(TG) analysis of the electrospun membrane were carried out to study the influence of the fibrous membrane structure on its comprehensive properties. The results show that the tensile strength of the five-layer fibrous membrane is 1.64 MPa and has a good heat resistance(the initial decomposition temperature reaches 445 ℃). Moreover, the fibrous membranes were activated to gel polymer electrolyte and assembled into a lithium-ion secondary battery. The electrolyte uptake of the five-layer fibrous membrane(PET-PVDF-5) is 2 818%, which is significantly higher than the single PVDF membrane. PET-PVDF-5 has high ionic conductivity(2.16 mS/cm), wide electrochemical stability window(4.85 V) and stable cycle charge-discharge performance after assembled into lithium ion secondary battery.