静电纺TiO2改性联苯型聚酰亚胺锂离子电池隔膜

先采用高压静电纺丝技术制备二氧化钛/聚酰胺酸(TiO₂/PAA)复合纤维膜，然后对其进行热亚胺化处理制备出二氧化钛/聚酰亚胺(TiO₂/PI)复合纤维隔膜。使用扫描电子显微镜(SEM)、傅里叶红外光谱分析仪(FTIR)、热失重分析仪和电化学工作站测试了TiO₂/PI复合纤维隔膜的基本性能和电化学性能，结果表明：隔膜具有明显的三维网状结构，与未改性的纯PI隔膜相比，改性后TiO₂/PI复合纤维隔膜的拉伸强度、孔隙率和吸液率分别提高到16.74 MPa、77.5%和550%；其热收缩性能较好，整体电化学性能优异。制备的LiFePO₄(磷酸铁锂正极)/TiO₂/PI/C(石墨负极)电池具有优异的循环稳定性和高放电容量，在1 C条件下进行100个循环后，其库伦效率在25℃和120℃高达96.7%和90.7%。

Electrospinning TiO2 Modified Biphenyl Polyimide Lithium Ion Battery Separator

TiO₂/PAA composite fiber membranes were prepared by high-voltage electrospinning, and then were thermally imidized to obtain TiO₂/PI composite fiber membranes. The physical properties, mechanical properties and electrochemical properties of TiO₂/PI composite fiber separators were assessed by means of scanning electron microscope, Fourier infrared spectrometer, thermogravimetric analyzer and electrochemical workstation. The results show that the membrane have clear three-dimensional network structure, and the tensile strength, the porosity and the liquid absorption rate of the modified TiO₂/PI composite membrane increase to 16.74 MPa, 77.5% and 550%, respectively comparing with the plain PI membrane; the membrane have good thermal shrinkage performance; excellent overall electrochemical performance; the prepared Li-battery of LiFePO₄ (lithium iron phosphate positive electrode)/TiO₂/PI/C (graphite negative electrode) presents excellent cycle stability and high discharge capacity, after 100 cycles at 1 C、at 25°C and 120°C, the cell coulombic efficiency is as high as 96.7% and 90.7%, respectively.