【摘要】 为了提高聚环氧乙烷(PEO)基电解质的离子电导率,通过分子接枝工程制备了一种由Cu-Al双金属有机框架(CAB)、锂盐(LiTFSI)和聚环氧乙烷PEO组成的复合固体电解质。实验和分子动力学模拟结果表明,含有10%CAB(质量分数)的电解质(PL-CAB-10%)具有较高的离子电导率(60℃时为8.42×10-4 S/cm)、较大的Li+转移数(0.46)、较宽的电化学窗口(4.91 V)、良好的热稳定性和优异的力学性能。此外,PL-CAB-10%在Li-Li对称电池和Li/PL-CAB-10%/LiFePO4非对称电池中均表现出优异的循环稳定性。其性能提升主要归因于多功能CAB的引入。CAB中的丰富金属位点可以通过Lewis酸碱相互作用与TFSI-和PEO反应,这既促进了LiTFSI的解离,又提高了离子电导率。同时,CAB中的规则孔洞为阳离子均匀涂覆提供了均一的分散位点。更多还原

【Abstract】 A composite solid electrolyte comprising a Cu-Al bimetallic metal-organic framework（CAB）,lithium salt（LiTFSI） and polyethylene oxide（PEO） was fabricated through molecular grafting to enhance the ionic conductivity of the PEO-based electrolytes.Experimental and molecular dynamics simulation results indicated that the electrolyte with 10 wt.% CAB（PL-CAB-10%） exhibits high ionic conductivity(8.42×10^-4 S/cm at 60℃),high Li+transference number（0.46）,wide electrochemical window（4.91 V）,good thermal stability,and outstanding mechanical properties.Furthermore,PL-CAB-10% exhibits excellent cycle stability in both Li-Li symmetric battery and Li/PL-CAB-10%/LiFePO4 asymmetric battery setups.These enhanced performances are primarily attributable to the introduction of the versatile CAB.The abundant metal sites in CAB can react with TFSI^-and PEO through Lewis acid-base interactions,promoting LiTFSI dissociation and improving ionic conductivity.Additionally,regular pores in CAB provide uniformly distributed sites for cation plating during cycling.更多还原