A room-temperature ionic liquid-based superionic conductive polymer electrolyte with high thermal stability for long-cycle-life lithium batteries
A room-temperature ionic liquid-based superionic conductive polymer electrolyte with high thermal stability for long-cycle-life lithium batteries
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DOI：
10.1007/s00396-022-05026-5
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发表时间：
2022-09
影响因子：
2.4
通讯作者：
Wenfeng Liang;Yuhan Zhang;Run Yang;Yu Zhu
中科院分区：
文献类型：
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作者：
Wenfeng Liang;Yuhan Zhang;Run Yang;Yu Zhu
将1-丁基-1-甲基吡咯烷双（三氟甲磺酰基）亚胺盐（[BMPy][TFSI]）、双（三氟甲磺酰基）亚胺锂盐（LiTFSI）、双（草酸）硼酸锂（LiBOB）和聚乙二醇二丙烯酸酯（PEGDA）混合，制备了室温离子液体基聚合物电解质（RTIL-PE）。准固体、独立式电解质膜可以通过光引发交联来制造。RTIL-PE在高达270 °C的温度下具有出色的热稳定性，在80 °C下具有3.4 mS/cm的高离子电导率。离子液体[BMPy][TFSI]和添加盐LiBOB显著提高了电解液在高温下的电化学稳定性，在镀/剥实验中实现了长循环稳定性。研究了以RTIL-PE和磷酸铁锂为正极的锂离子电池半电池。电池在0.2C时的可逆容量达到137 mAh/g。在500次循环后，电池表现出52.2%的容量留存率和99.4%的平均库仑效率。
A room-temperature ionic liquid-based polymer electrolyte (RTIL-PE) was developed by mixing 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([BMPy][TFSI]), lithium bis(trifluoromethanesulphonyl)imide salt (LiTFSI), lithium bis(oxalate)borate (LiBOB) and poly(ethylene glycol) diacrylate (PEGDA). Quasi-solid, free-standing electrolyte membranes can be fabricated by photo-initiated cross-linking. The RTIL-PE exhibits outstanding thermal stability up to 270 °C and high ionic conductivity of 3.4 mS/cm at 80 °C. The ionic liquid [BMPy][TFSI] and the additive salt LiBOB significantly improved the electrochemical stability of the electrolyte at high temperature, achieving long-cycle stability in plating/stripping experiments. Half cells of lithium-ion batteries with RTIL-PE and lithium iron phosphate cathode were also investigated. The reversible capacity of the cell reaches 137 mAh/g at 0.2 C. After 500 cycles, the cell exhibited a capacity retention rate of 52.2% and an average Coulombic efficiency of 99.4%.Graphical abstract