聚苯并咪唑-锂盐-聚乙二醇单甲醚共混全固态聚合物电解质的制备及性能

使用共混后浇铸成膜的方法,制备了聚苯并咪唑-锂盐-聚乙二醇单甲醚组成的锂离子电池共混全固态聚合物电解质。通过傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、差示扫描量热(DSC)、拉伸与交流阻抗测试表征了共混全固态电解质的结构与性能。研究了不同锂盐以及各组分含量对共混全固态电解质的力学性能与电导率的影响。结果表明:聚苯并咪唑与聚乙二醇单甲醚之间存在氢键;共混全固态电解质中聚乙二醇单甲醚处于无定形态;锂盐的加入使聚乙二醇单甲醚的玻璃化转变温度下降;聚乙二醇单甲醚含量越高,共混膜强度越低,电导率越高,并且使用三氟甲磺酸锂作为锂盐时其电导率最高,室温下可以达到3.58×10~(-5) S/cm,高温下可以达到3.3×10~(-3) S/cm,高温下满足对锂离子电池的使用需求。

Preparation and Properties of Polybenzimidazole-Lithium Salt-Poly(ethylene glycol) Monomethyl Ether Blend All Solid Polymer Electrolyte

A series of polybenzimidazole-lithium salt-poly(ethylene glycol) monomethyl ether blend all solid polymer electrolyte membranes were prepared through solution casting method.FT-IR, XRD, DSC and EIS measurements were used to characterize the structure and test properties of blend all solid polymer electrolyte.The influences of different component contents on mechanical strength and ionic conductivity were researched.The results showed that hydrogen bond between polybenzimidazole and poly(ethylene glycol) monomethyl ether existed;In the blend all solid polymer electrolyte, poly(ethylene glycol) monomethyl ether was amorphous;The glass transformation temperature(Tg) of poly(ethylene glycol) monomethyl ether decreased as the add of lithium salt;Blend all solid polymer electrolyte with higher poly(ethylene glycol) monomethyl ether content showed higher ionic conductivity and worse mechanical properties.Blend all solid polymer electrolyte with lithium trifluoromethanesulfonate showed higher ionic conductivity;the highest conductivity of these blend all solid polymer electrolytes was 3.58×10-5 S/cm at room temperature and 3.3×10-3 S/cm at high temperature, which can satisfy the lithium-ion battery used at high temperature.