一种新型凝胶态聚合物电解质的制备和性能

采用一种新型胶联剂新戊二醇二丙烯酸酯(noepentyl glycol diacrylate, NPGDA)和聚偏氟乙烯-六氟丙烯(poly(vinylidene fluoride-co-hexafluoropropylene), PVDF-HFP), 液态电解液组成电解质混合溶液, 然后加入引发剂并加热引发聚合反应制备了一种具有互穿聚合物网络结构的凝胶态聚合物电解质, 可以用于制备聚合物锂离子二次电池. 考察了不同PVDF-HFP/NPGDA质量比对凝胶态聚合物电解质性能的影响. 结果表明, PVDF-HFP/NPGDA质量比可以影响凝胶态聚合物电解质的结构形貌、电化学特性以及聚合物锂离子二次电池的性能. 研究发现, 当m(PVDF-HFP)/m(NPGDA)＝1:1时制备的凝胶态聚合物电解质具有较高的离子电导率和电化学稳定窗口, 室温下分别为6.99×10^-3 S?cm^-1和4.8 V(vs Li⁺/Li), 以其为电解质制备的聚合物锂离子二次电池具有较好的电化学性能.

Preparation and Performances of a Novel Gel Polymer Electrolyte

A novel gel polymer electrolyte (GPE) based on noepentyl glycol diacrylate (NPGDA) and poly(vinyli-dene fluofide-co-hexafluoropropylenen) (PVDF-HFP) was prepared by a thermal polymerization method. GPE with a stable interpenetrating polymer network (IPN) structure was used to assemble polymer lithium-ion batteries. The influence of PVDF-HFP/NPGDA mass ratios on the characteristics of GPE was studied by scanning electron microscopy, linear sweep voltammetry and electrochemical impedance spectroscopy. The results show that PVDF-HFP/NPGDA mass ratio greatly affects the performances of GPE, such as surface morphology and ionic conductivity. When the mass ratio between PVDF-HFP and NPGDA is 1:1, GPE boasts a high ionic conductivity of 6.99×10^-3 S?cm^-1 and an electrochemical stability window of 4.8 V(vs Li⁺/Li) at 25 ℃. The polymer lithium-ion batteries based on GPE also present excellent performances, such as high rate capability and discharge voltage plateau, good temperature reliability, and excellent cycling.