梳状热塑性聚氨酯基固态聚合物电解质的制备与性能

Solid Polymer Electrolytes Based on Comb-Like Thermoplastic Polyurethane

以三羟甲基丙烷聚乙二醇单甲醚(Ymer-N120)、聚对苯二甲酸-3-甲基-1,5-戊二醇酯二醇(TPA-1000)、异佛尔酮二异氰酸酯和1,4-丁二醇合成了系列具有梳状结构的热塑性聚氨酯弹性体(TPU),再在TPU中加入锂盐得到系列固态聚合物电解质(SPEs);研究了TPA-1000和Ymer-N120加入量对固态聚合物电解质性能的影响。结果表明,制备的SPEs离子电导率与温度的关系符合Arrhenius方程,随着Ymer-N120含量的增加,SPEs的玻璃化转变温度降低,拉伸强度减小,其中以质量比m(TPA-1000)∶m(Ymer-N120)=1∶2制备的固态聚合物电解质(SPE4)综合性能最佳,拉伸强度为0.88 MPa、80℃时离子电导率为1.07×10^(-4) S/cm,以SPE4组装的LiFePO_4/SPE4/Li全固态电池在80℃、0.2 C下的放电比容量为138 mA·h/g。

A series of comb-like thermoplastic polyurethane (TPU) with trimethylolpropane polyethylene glycol monomethyl ether(Ymer-N120), poly-terephthalic acid-3- methyl-1,5-amyl glycol ester diol(TPA-1000), isophorone diisocyanate and 1,4-butanediol were synthesized. Solid polymer electrolytes (SPEs) were fabricated by adding LiTFSI to TPU with the content of 20%. The influence of the amount of TPA-1000 and Ymer-N120 on properties of the SPEs was discussed. The results show that the relationship between the ionic conductivity of the SPEs and temperature is consistent with the Arrhenius equation. The glass transition temperature and tensile strength decrease with the increase of Ymer-N120 content. The comprehensive properties of electrolyte are obtained when the mass ratio of Ymer-120 and TPA-1000 is 1∶2 (SPE4). The tensile strength of SPE4 is 0.88 MPa with the ionic conductivity of 1.07× 10^-4 S/cm at 80 ℃. The discharge capacity of the solid-state lithium battery assembled by SPE4 reaches 138 mA·h/g at 0.2 C under 80 ℃.