PVDF/PMMA/PEG型聚合物隔膜的制备

PVDF/PMMA/PEG polymer diaphragm preparation

为提高锂离子电池聚偏氟乙烯(PVDF)基聚合物隔膜对电解液体系的亲和性和导电性,引入聚甲基丙烯酸甲酯(PMMA)与聚偏氟乙烯(PVDF)进行共混,并添加有机增塑剂聚乙二醇PEG-400对PVDF基聚合物隔膜进行改性研究。采用先干法后湿法的相转化方法制备PVDF/PMMA/PEG型聚合物隔膜。通过对制备的聚合物隔膜的孔隙率、吸液率、微观形貌和电化学性能的分析研究,确定制膜的最佳工艺条件为聚合物占溶剂质量百分比为8%,PVDF∶PMMA=7∶3,增塑剂含量为30%,非溶剂含量为3%,反应温度为45℃,在此最佳工艺条件下制备的PVDF/PMMA/PEG隔膜的离子电导率可达2.848 m S/cm,对电解液体系的亲和性和导电性得到显著提高。

Lithium ion battery gel polymer electrolyte used instead of traditional liquid electrolyte has many advantages,the gel is a kind of special state between solid and liquid,gel polymer electrolyte has both solid electrolyte and good mechanical properties,but also has similar conductivity of liquid electrolyte ion,which plays an important role to improve the comprehensive performance of the battery. The main research of this topic is the contents for modified the PVDF polymer material,the concrete content is that blend PVDF and PMMA polymer,then add the plasticizing PEG-400,with the modified of the wet process( dry-wet process) to make it. Through testing the porosity and fluid absorption rate,the combination of scanning electron microscopy SEM and electrochemical workstation to test the sample characterization,finally the best one is: polymer of solvent percentage is 8%,PVDF∶ PMMA = 7∶ 3,plasticizer content is 30%,the solvent content is 3%,the reaction temperature is 45 ℃. Ionic conductivity of PVDF / PMMA / PEG polymer of up to 2. 848 mS /cm,the electrolyte system compatibility and conductivity is significantly improved.