基于Cu-Al双金属有机框架的分子接枝提高固体聚合物电解质的离子电导率

Improvement of ionic conductivity of solid polymer electrolyte based on Cu-Al bimetallic metal-organic framework fabricated through molecular grafting

宋刘斌 ¹龙田源 ²肖敏之 ²刘敏 ³赵亭亭 ¹匡尹杰 ¹蒋琳 ²肖忠良¹

扫码查看

作者信息

1. 长沙理工大学化学与化学工程学院,长沙 410114;长沙理工大学电力与交通材料保护湖南省重点实验室,长沙 410114
2. 长沙理工大学化学与化学工程学院,长沙 410114
3. 宁波工程学院新能源学院,宁波 315336
折叠

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.

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.

关键词

聚环氧乙烷/铜铝双金属有机框架/固体锂金属电池/分子接枝/离子电导率

Key words

polyethylene oxide/Cu-Al bimetallic metal-organic framework/solid lithium metal battery/molecular grafting/ionic conductivity

引用本文复制引用

基金项目

National Natural Science Foundation of China(21501015)

Hunan Provincial Natural Science Foundation,China(2022JJ30604)

Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation,China(2022CL01)

出版年

2024

中国有色金属学报(英文版)

中国有色金属学会

中国有色金属学报(英文版)

CSTPCDCSCD

影响因子：1.183

ISSN：1003-6326

参考文献量4

段落导航