新型共混的PEO/TPU/PVDF-HFP基聚合物电解质的制备及性能

Preparation and properties of new blended PEO/TPU/PVDF-HFP-based polymer electrolyte

摘要:

通过相转化法制备基于聚氧化乙烯（PEO）/热塑性聚氨酯（TPU）/聚偏氟乙烯-六氟丙烯（PVDF-HFP）三种高聚物共混形成的电解质隔膜, 浸泡在1 mol/L六氟磷酸锂（LiPF6）的碳酸乙烯酯（EC）: 碳酸二甲酯（DMC）: 碳酸甲乙酯（EMC）=1:1:1的电解液中形成一种新型的凝胶态聚合物电解质（GPE）。采用SEM、FTIR、XRD、TG、DSC、拉伸性能和电化学性能进行了表征。结果表明，聚合物配比为3:1:4的隔膜具备均匀的多孔形貌，结晶峰面积最低，拉伸强度达到了15 MPa，离子电导率为7.9?10^(-3) S?cm，综合性能最佳。将聚合物配比为3:1:4的隔膜装配成CR2032纽扣电池进行电池循环性能测试，结果表明，在0.2 C下电池的充放电比容量分别达到了164 mAh/g和161 mWh/g，在150次循环后，放电比容量仍能保持在152 mAh/g 左右，库仑效率保持97%以上，是一种优异的电池材料。

Abstract:

An electrolyte separator based on the blending of three polymers of polyethylene oxide (PEO)/thermoplastic polyurethane (TPU)/polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) was prepared by phase inversion method. It was soaked in electrolyte which contains 1 mol /L lithium hexafluorophosphate (LiPF6) ethylene carbonate (EC): dimethyl carbonate (DMC): ethyl methyl carbonate (EMC) = 1:1:1 to form a new type of gel polymer electrolyte (GPE). Characterized by SEM, FTIR, XRD, TG, DSC, tensile properties and electrochemical properties. The results showed that the membrane with a polymer ratio of 3:1:4 has a uniform porous morphology, the crystalline peak area is the lowest, the tensile strength reaches 15MPa, and the ion conductivity is 7.9?10^(-3) S?cm，, the best overall performance. The separator with a polymer ratio of 3:1:4 was assembled into a CR2032 button battery for battery cycle performance testing. The results showed that the charge-discharge specific capacity of the battery reached 164 mAh/g and 161 mWh/g at 0.2 C, After 150 cycles, the discharge specific capacity can still be maintained at about 152 mAh/g, and the Coulomb efficiency remains above 97%, making it an excellent battery material.