聚乙烯醇交联改性聚乙烯锂离子电池隔膜的制备

将聚乙烯(PE)隔膜用乙醇润湿,然后将其放入聚乙烯醇(PVA)溶液中浸润,使PVA进入隔膜孔结构中,再将隔膜放入交联溶液[pH=2,25%(w)戊二醛]中进行交联反应,制备了PVA交联改性PE隔膜。采用傅里叶变换红外光谱和能量色散X射线光谱对隔膜的表面与断面进行了表征,并研究了改性隔膜的物理性能及电池性能。结果表明:PVA交联改性PE隔膜的表面亲水性和抗高温热收缩性提高,瞬时水接触角由初始的98.6°降至66.5°,且组装的锂离子电池的循环性能和倍率容量均有一定程度的改善,PE隔膜的离子电导率由0.463 mS/cm升至0.864 mS/cm。

Preparation of polyvinyl alcohol crosslinking modified PE separator for lithium-ion battery

The polyethylene(PE)separator was wet with ethanol and put into polyvinyl alcohl(PVA)solution to infiltrate,which helps PVA to enter the pore structure of the separator.The separator was then put into the cross-linking solution in which the mass fraction of glutaraldehyde is 25%and pH value is 2 for crosslinking reaction to prepare PVA crosslinking modified PE separator.The surface and the cross-section of the separator were characterized by Fourier transform infrared spectroscope and energy dispersive spectrometer.The physical properties and battery performance of the separator was studied as well.The results show that the surface hydrophilicity and high temperature thermal shrinkage resistance of PVA crosslinking modified PE separator are improved,whose instantaneous water contact angle is reduced from the initial 98.6°to 66.5°.The cycle and rate capacity of the assembled lithium-ion battery are improved to a certain extent.The ionic conductivity of the PE separator is increased from 0.463 mS/cm to 0.864 mS/cm.