苯酐改性聚乙二醇型聚氨酯固态电解质的制备与性能

Preparation and properties of polyethylene glycol-based polyurethane solid electrolyte with the modification of terephthalic anhydride

摘要:

以异佛尔酮二异氰酸酯（IPDI）、聚对苯二甲酸-3-甲基-1,5-戊二醇酯二醇（TPA-1000）、聚乙二醇（PEG-2000）、一缩二乙二醇（DEG）为主要原料合成了一系列热塑型聚氨酯弹性体，然后加入20%的锂盐（LiTFSI）制备不同的全固态电解质（SPE）。结果表明，随着TPA-1000含量的减少和PEG-2000含量的增加，SPE的耐热性增加，玻璃化转变温度减小，拉伸强度减小，断裂伸长率增加。SPE的离子电导率与温度的关系基本符合Arrhenius方程，在80℃，SPE（除纯PEG-2000的电解质外）的电化学窗口均达到4.0V以上，其中质量比TPA-1000：PEG-2000=1：2（SPE4）综合性能最佳，力学为1.87Mpa、电导率为2.15?10-4 S cm-1、窗口为4.3V。以SPE4组装的全固态电池在80℃、0.2C下放电比容量为150 mAh/g。

Abstract:

A series of thermoplastic polyurethane with isophorone diisocyanate (IPDI), Poly-terephthalic acid-3-methyl-1,5-amyl glycol ester diol (TPA-1000), polyethylene glycol (PEG-2000) and diethylene glycol (DEG) were synthesized . The 20wt% lithium salt was added to prepare all-solid-polymer electrolyte (SPE). The results showed that with the decrease of TPA-1000 and the increase of PEG-2000 , the heat resistance of SPE increasing, the glass transition temperature decreasing, the tensile strength decreasing and the elongation at break increasing. The relationship between ionic conductivity and temperature was accorded with the Arrhenius equation. The electrochemical windows of SPE except for the pure PEG-2000 were all above 4.0V at 80 ℃. When TPA-1000 and PEG-2000 had a mass ratio of one to two (SPE4), the comprehensive properties of electrolyte was the best. The mechanical strength was 1.87 Mpa, the conductivity was 2.15?10-4 S cm-1 and the electrochemical window was 4.3V. The discharge of all-solid-state battery assembled with SPE4 can reach 150 mAh/g at 0.2 C under 80 ?C.