原位交联凝胶聚合物电解质的制备及性能

采用相转化法制备了聚偏氟乙烯(PVDF)和苯乙烯-氧化乙烯-苯乙烯三嵌段共聚物(PS-PEO-PS)的共混多孔前体膜,再利用芳香官能团的傅克反应将前体膜原位交联,交联膜吸收电解液后得到交联凝胶聚合物电解质(CPEs)。对交联膜的形貌、热稳定性以及CPEs的电化学性能进行了表征,探讨了嵌段共聚物中PEO的链段长度对CPEs综合性能的影响。结果表明,CPEs交联膜的孔隙率和热稳定性较纯PVDF膜有很大的提升,其中CPE-2交联膜的孔隙率最高为72.3%,300℃时仍能保持稳定的孔隙结构,且几乎没有尺寸收缩,测试用半电池室温下显示出高的离子电导率(2.09mS/cm)和良好的充放电性能。

Preparation and Properties of In Situ Cross-Linked Gel Polymer Electrolytes

The crosslinked gel polymer electrolytes (CPEs) were fabricated via combination of physical blending and chemical cross-linking procedures.PVDF/PS-PEO-PS precursor membranes were prepared by phase inversion technique and then followed by in situ cross-linking process based on the Friedel-Crafts reaction of aromatic groups.The morphology,thermal stability and electrochemical properties of CPEs were characterized and the effect of PEO chain length of the copolymers on the properties of CPEs was discussed.The results show that the porosity and thermal stability of CPE membranes are greatly improved compared with pure PVDF membranes.The CPE-2 membrane shows the highest porosity (72.3％) and remains stable pore configuration up to 300 ℃ with little dimensional shrinkage.When assembled into batteries,CPE-2 shows a high ionic conductivity (2.09 mS/cm) and good charge-discharge performance.