PVDF/SiO_2复合纤维膜的制备及电化学性能

Preparation and Electrochemical Properties of PVDF/SiO_2 Composite Fibrous Membranes

采用静电纺丝法制备了SiO2含量分别为2%、5%和8%的PVDF/SiO2复合纤维膜,对复合纤维膜的物理性能、电化学性能以及组装电池性能等进行了测试分析。结果表明:纳米SiO2含量对静电纺PVDF基膜的纤维直径和形貌影响很大,随着SiO2含量的增加,静电纺PVDF/SiO2复合纤维膜的纤维直径变细且分布变宽,纤维表面的均匀性降低;其力学性能、电解液吸液率以及离子电导率均先增加后降低。以含量为5%的SiO2静电纺PVDF/SiO2复合纤维膜为隔膜组装的电池首周充放电容量最高,约为158 m Ah/g;经过50周充放电循环后,电池的容量保持率最高为91%。

PVDF/SiO2 composite fibrous membranes with 2%, 5%, and 8% of SiO2 were prepared by electrospirming method respectively, and their mechanical properties and electrochemical properties were tested as well as the performance of assembled battery. The results show that the addition of SiO2 has great influence on the fiber diameter and morphology of electrospinning PVDF composite membranes. With the increase of SiO2 content, the fiber diameter and its distribution of the PVDF/SiO： composite membrane become thinner and wider, and the surface uniformity of fiber reduces; its mechanical properties, electrolyte uptake, and ionic conductivity increase at first and then decrease. The battery, assembled using PVDF/ SiO： composite membrane with 5% of SiO2, shows good charge and discharge performance, and its first discharge capacity is 158 mAh/g. The capacity retention ratio could reach 91% after 50 charge-discharge cycles.