Revealing the role and working mechanism of confined ionic liquids in solid polymer composite electrolytes  

作　　者：Haiman Hu Jiajia Li Yue Wu Wenhao Fang Haitao Zhang Xiaoyan Ji 

机构地区：[1]Energy Engineering,Division of Energy Science,Lulea University of Technology,97187 Luled,Sweden [2]Beijing Key Laboratory of Ionic Liquids Clean Process,Institute of Process Engineering,Chinese Academy of Sciences,Beiing 100190,China

出　　处：《Journal of Energy Chemistry》2024年第12期110-119,共10页能源化学（英文版）

基　　金：support from European Union’s Horizon 2020 research,innovation programme under grant agreement No. 958174, Vinnova (Swedish Governmental Agency for Innovation Systems);the financial support from the LTU CREATERNITY program;the J. Gust Richert Foundation;the Swedish Energy Agency,STINT (CH2019-8287),and Bio4energy;the National Natural Science Foundation of China (No.U23A20122)。

摘　　要：The confined ionic liquid(IL) in solid polymer composite electrolytes(SCPEs) can improve the performance of lithium metal batteries. However, the impact/role and working mechanism of confined IL in SCPEs remain ambiguous. Herein, IL was immobilized on SiO_(2)(SiO_(2)@IL-C) and then used to prepare the confined SCPEs together with LiTFSI and PEO to study the impacts of confined-IL on the properties and performance of electrolytes and reveal the Li+transport mechanism. The results show that, compared to the IL-unconfined SCPE, the IL-confined ones exhibit better performance of electrolytes and cells, such as higher ionic conductivity, higher t+Li, and wider electrochemical windows, as well as more stable cycle performance, due to the increased dissociation degree of lithium salt and enlarged polymer amorphousness. The finite-element/molecular-dynamics simulations suggest that the IL confined on the SiO_(2) provided an additional Li+transport pathway(Li+→ SiO_(2)@IL-C) that can accelerate ion transfer and alleviate lithium dendrites, leading to ultrastable stripping/plating cycling over 1900 h for the Li/SCPEs/Li symmetric cells. This study demonstrates that IL-confinement is an effective strategy for the intelligent approach of high-performance lithium metal batteries.

关 键 词：Ionic liquid CONFINEMENT Ionic transport pathway Lithium-ion transport kinetics Lithium metal batteries 

分 类 号：TM912[电气工程—电力电子与电力传动] O645.1[理学—物理化学] O646[理学—化学]