聚丙烯亲水性微孔膜的制备及在锂电池中的应用

发布时间：2018-10-20 11:18

【摘要】：以聚丙烯接枝马来酸酐(PP-g-MAH)为改性剂与聚丙烯熔融共混,通过单向拉伸工艺制备亲水性聚丙烯微孔膜。使用差示扫描量热仪和红外光谱表征流延基膜的取向片晶结构,使用压汞仪和扫描电镜表征微孔膜的孔结构,使用Gurley值、水接触角和水蒸气透过率表征微孔膜的透过性和亲水性,将微孔膜组装成电池并测定电池的性能,研究PPg-MAH含量对微孔膜孔结构、亲水性、透过率及电池性能的影响。结果表明,PP-g-MAH共混含量为2.5%的微孔膜孔隙率和透气性得到提升,进一步增加PP-g-MAH含量会导致微孔膜孔结构变差,透过性能下降。微孔膜表面亲水性随PP-g-MAH含量增加持续改善,水蒸气透过率在PP-g-MAH含量为5%时达到最大值,但由于微孔膜孔结构在较高PPg-MAH含量下受到破坏,使得高PP-g-MAH含量下微孔膜水蒸气透过率下降。PP-g-MAH含量为2.5%和5%的微孔膜由于具有较好的孔结构和一定的电解液浸润性,使得锂电池的电荷转移电阻较低,首次充放电比容量较高。
[Abstract]:The hydrophilic polypropylene microporous membrane was prepared by uniaxial stretching process using polypropylene graft maleic anhydride (PP-g-MAH) as modifier and polypropylene melt blend. The oriented lamellar structure of the film was characterized by differential scanning calorimetry (DSC) and infrared spectroscopy (IR). The pore structure of the film was characterized by mercury porosimeter and scanning electron microscope (SEM), and the Gurley value was used. The water contact angle and water vapor transmittance were used to characterize the transmissivity and hydrophilicity of the microporous membrane. The microporous membrane was assembled into a battery and the performance of the battery was measured. The effects of PPg-MAH content on the pore structure, hydrophilicity, transmittance and battery performance of the microporous membrane were studied. The results showed that the porosity and gas permeability of the microporous membrane with 2.5% PP-g-MAH blend were improved, and further increase of the PP-g-MAH content would lead to the deterioration of the pore structure and the decrease of the permeability of the microporous membrane. The surface hydrophilicity of the microporous membrane continuously improved with the increase of PP-g-MAH content, and the water vapor transmittance reached the maximum when the PP-g-MAH content was 5, but the pore structure of the microporous membrane was destroyed under the higher PPg-MAH content. The water vapor transmittance of microporous membrane decreases with high PP-g-MAH content, and the charge transfer resistance of lithium battery with 2.5% and 5% PP-g-MAH content is lower and the first charge / discharge specific capacity is higher because of its good pore structure and certain electrolyte wettability.
【作者单位】：常州大学材料科学与工程学院江苏省光伏科学与工程协同创新中心;
【基金】：江苏高校优势学科建设工程资助项目
【分类号】：TQ325.14;TM912

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