Difunctional NH2-modified MOF supporting plentiful ion channels and stable LiF-rich SEI construction via organocatalysis for all-solid-state lithium metal batteries
Difunctional NH2-modified MOF supporting plentiful ion channels and stable LiF-rich SEI construction via organocatalysis for all-solid-state lithium metal batteries
复制标题
双功能NH2修饰的MOF通过有机催化支持丰富的离子通道和稳定的富含LiF的SEI结构用于全固态锂金属电池
DOI：
10.1016/j.jmst.2022.07.017
复制
发表时间：
2022
影响因子：
10.9
通讯作者：
Zengsheng Ma
中科院分区：
文献类型：
--
作者：
Xuanyi Zhou;Christopher Y. Li;Biao Zhang;Fenfen Huang;Pan Zhou;Xinming Wang;Zengsheng Ma
作为锂金属电池性能提升的重要组成部分，致密（富含LiF的固体电解质中间相（SEI））的获取一直是亟待解决的问题。在此，我们合成了由两种不同官能团（-NH2、-CH3）修饰的沸石咪唑酯骨架（ZIF），并将其用作聚环氧乙烷（PEO）复合固体电解质的填料，探讨基团对Li/电解质界面生成LiF的催化作用。在LiFePO4||SPE||Li电池测试中，富含LiF SEI的PEO-ZIF-NH2表现出增强的循环性能，比PEO-ZIF-CH3长3.8倍。利用第一性原理计算研究了富含LiF的SEI的形成机制，发现ZIFs-NH2使TFSI中的C-F键比ZIFs-CH3更长，这导致C-F键更容易断裂并促进LiF的形成。利用有机催化生成更稳定的SEI的简单设计思路为制备高性能锂金属电池提供了新的思路。
As an essential part of the performance improvement of lithium metal batteries, the acquisition of dense (LiF-rich solid electrolyte interphase (SEI)) has always been an urgent problem to be solved. Herein, we synthesized Zeolitic Imidazolate Frameworks (ZIFs) modified by two different functional groups (–NH2, –CH3) and used them as the fillers of polyethylene oxide (PEO) composite solid electrolytes to explore the catalytic effect of groups on LiF generation at the Li/electrolytes interface. In a LiFePO4||SPE||Li cell test, the PEO-ZIF-NH2with LiF-rich SEI exhibits enhanced cycling performance, which was 3.8 times longer than that of PEO-ZIF-CH3. The formation mechanism of LiF-rich SEI was investigated using first-principles calculation, revealing that ZIFs-NH2makes the C–F bond in TFSI–longer compared with ZIFs-CH3, which leads to easier breakage of the C–F bond and promoted the formation of LiF. The simple design idea of using organic catalysis to generate more stable SEI provides a new aspect for preparing high-performance lithium metal batteries.