静电纺丝聚芳醚砜酮纤维膜穿刺强度研究

静电纺丝纤维膜因为具有高孔隙率、大的比表面积和良好的电解液润湿性而被广泛地应用于锂离子电池隔膜的研究,但对于锂离子电池安全性能至关重要的隔膜穿刺强度的研究还比较匮乏。本工作采用静电纺丝技术制备得到PPESK纤维膜,并采用热处理提高纤维膜的力学性能,然后通过穿刺实验测得一系列不同厚度热处理PPESK纤维膜的穿刺强度,并建立起穿刺强度与纤维膜厚度之间的线性关系。通过对穿刺破坏区域的微观分析,探究热处理PPESK纤维膜穿刺破坏机理,结果表明:各向同性的热处理PPESK纤维膜穿刺过程是由纤维受挤压产生弯曲、变形和断裂造成的破坏,破坏区域呈近似圆形穿刺孔,而PP微孔膜的破坏区域则是由脆性断裂造成的长条形裂缝,相比之下热处理PPESK纤维膜的穿刺破坏过程更加缓和,可以降低锂枝晶刺穿隔膜带来的风险,但是热处理PPESK纤维膜的穿刺强度还有待增强。

Puncture strength research of electrospun PPESK fibrous membrane

Electrospun fibrous membranes have been widely used for research of lithium-ion battery separators because of the high porosity,large specific surface area as well as excellent electrolyte wettability.However,little research has been focused on the puncture strength,which influences the safety of lithium-ion battery seriously.PPESK fibrous membranes with different thicknesses were fabricated by electrospinning technique,and the mechanical properties were improved by heat treatment,and the puncture strength of heat-treated PPESK membrane was tested using universal tensile testing machine and the linear relationship between the puncture strength of heat-treated PPESK fibrous membrane and the thickness was established.The further microscopic analysis of the puncture failure region was carried out to explore the puncture failure mechanism of heat-treated PPESK fibrous membranes.The result shows that the puncture process of isotropic heat-treated PPESK fibrous membrane is much tempered compared with PP microporous separator.The penetration of the heat-treated PPESK fibrous membranes was caused by the bend,deformation and fracture of PPESK fibers.The failure region of heat-treated PPESK fibrous membrane appears a circular hole,while the PP separator is long cracks.The puncture mechanism of heat-treated PPESK fibrous membrane is beneficial to prevent the destruction of lithium dendrites,but the puncture strength of heat-treated PPESK fibrous membrane remains to be enhanced.