摘要
文中介绍了一种制备纳米复合膜的方法——同轴静电共喷纺.首先组装了由外喷嘴和内喷嘴构成的同轴共喷纺装置,将静电纺丝与静电喷涂结合起来,利用该技术制备纳米纤维/颗粒复合膜.将聚偏氟乙烯(PVDF)/SiO2溶于N,N-二甲基甲酰胺(DMF)中,从外喷口制备颗粒;PVDF溶于DMF和丙酮混合物中,从内喷口制备纤维,成功制备了同时含颗粒和纤维的PVDF&PVDF/SiO2复合膜,复合膜中颗粒的平均粒径为2.01 μm,纤维平均直径为0.43 μm.然后将PVDF&PVDF/SiO2复合膜原位涂覆在商用超高分子量聚乙烯(UHMWPE)隔膜上,从而制备了一种新型锂离子电池复合隔膜.测试结果表明,该复合隔膜的孔隙率为85.96%,比UHMWPE基材膜的37.85%有明显的提高,纵向收缩率由7.28%降低到5.26%,复合隔膜接触角由48.55°降低到14.93°.与未改性的商用隔膜相比,同轴静电共喷纺制备的复合隔膜首次充放电比容量由107.8 mAh/g提高到122.4 mAh/g,经50次循环后,仍具有良好的循环稳定性.
Abstract
A technology named coaxial electro-spraying/electrospinning for preparing composite membranes was introduced.First,the coaxial electro-spraying/electrospinning equipment was assembled,which includes an outer nozzle and an inner nozzle.Then the method was studied for the preparation of fiber/particle composite membranes.Polyvinylidene fluoride(PVDF)/SiO2 in DMF was utilized to prepare the particles from the outer nozzle of the equipment,and PVDF dissolved in a mixture of DMF and acetone was used to prepare the fibers from the inner nozzle of the equipment.The PVDF&PVDF/SiO2 composite membranes including particles and fibers were successfully prepared at the same time by the equipment.The analytical results show that the average fiber diameter is 0.43 μm,and the average particle size is 2.01 μm.Then the modified composite materials were in situ loaded on ultra-high molecular weight polyethylene(UHMWPE)to prepare a new Li-ion battery separator.According to the analytical data,the porosity of the composite separator is 85.96%,which is significantly higher than the 37.85%of the UHMWPE separator.The longitudinal shrinkage decreases from 7.28%to 5.26%,respectively.The compound separator contact angle reduces from 48.55° to 14.93°.The initial charge-discharge specific capacity of the experimental separator is increased from 107.8 mAh/g to 122.4 mAh/g compared to the unmodified separator.After 50 cycles,it still exhibits a good cycling stability.
基金项目
科研基地-科技创新平台-新材料研究与开发(11011021001)
NETL
NSTL
维普
万方数据