含PVDF-HFP多孔骨架和交联PEG的锂离子凝胶膜制备与性能

Preparation and property of gel membranes containing porous PVDF-HFP and crosslinked PEG for lithium ion conduction

锂离子导电膜是锂离子电池的核心材料,研究了以可溶胀聚合物多孔膜作为骨架、在其孔道内填充凝胶结构而制备的锂离子导电膜。首先采用溶液相转化法制备了聚(偏氟乙烯-六氟丙烯)(PVDF-HFP)多孔膜,然后将多孔膜浸入含有锂盐、聚乙二醇二丙烯酸酯(PEGDA)和过氧化苯甲酰的碳酸酯溶液吸收电解液,再加热引发PEGDA中双键交联得到具有多孔骨架和交联PEG的锂离子凝胶聚合物电解质膜(Li-GPEM)。失重、力学和及电化学性质分析表明,所制备的Li-GPEM的电导率为2.25mS/cm,综合性能优于PVDF-HFP多孔膜吸附液态锂盐溶液的体系和共混凝胶膜体系。

Lithium ion conducting membranes are the key materials for lithium batteries. The lithium ion conducting gel polymer electrolyte membranes （Li-GPEMs） containing PVDF-HFP porous matrix filled with crosslinked PEG network are presented and prepared via the following route. The porous membranes of PVDF- HFP are obtained by typical phase inversion process. By immersing porous PVDF-HFP membrane in liquid electrolyte containing PEGDA at 25℃ to absorb the liquid electrolyte,and then thermal crosslinking at 60℃,the Li- GPEMs are fabricated successfully. The measurements in weight loss, mechanics and electrochemistry reveal that the obtained Li-GPEMs have the better overall performances than the liquid or blend gel system while being used as conduction medium in lithium batteries. The highest conductivity of Li-GPEM can reach as high as 2.25 × 10^-3S/cm.