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Bidentate Phosphonate‐Functionalized Ionic Liquid Exhibiting Better Ability in Improving the Performance of Lithium‐Ion Battery
Author(s) -
Sang Kunming,
Wang Binbin,
Ge Jiawen,
Zhu Taofeng,
Jiang Yufei,
Zhao Lingling,
Zhou Mingjiong,
Liang Hongze
Publication year - 2021
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.202004804
Subject(s) - phosphonate , ionic liquid , electrochemistry , lithium (medication) , electrolyte , dielectric spectroscopy , inorganic chemistry , ionic conductivity , ion , chemistry , materials science , organic chemistry , electrode , catalysis , medicine , endocrinology
In this work, flame retarding phosphonate‐functionalized imidazolium ionic liquids (PFILs) were synthesized and employed as electrolyte additives for Li/LiFePO 4 half‐cells. Physical and electrochemical properties, including ionic conductivity, electrochemical properties, electrochemical oxidation limit, electrochemical impedance spectroscopy (EIS) and lithium‐ion transference number (T Li + ), were investigated. The results demonstrate that the addition of PFIL can improve the electrochemical performance of lithium‐ion batteries (LIBs). Hybrid electrolyte with 10 wt % bidentate phosphonate‐functionalized imidazolium ionic liquid (b‐PFIL) exhibits more excellent electrochemical oxidation stability (up to 4.77 V vs. Li/Li + ), capacity retention (87.3 % after 400 cycles) and rate capability. These improvements can be ascribed to the enhanced lithium‐ion transference number (T Li + ), which results from the stronger binding affinity between chelating b‐PFIL and LiPF 6 .