Corresponding Author

Pei-xia YANG(yangpeixia@hit.edu.com)


Ionically conductive gel polymer electrolyte is an excellent candidate due to its inflammable, nonvolatile and high thermal stability as compared to commercial liquid electrolytes which are usually flammable, volatile, and containing toxic organic solution as solvent, The synthesis and application of ionic gel polymer electrolytes in lithium ion/metal batteries have been previously reported. However, the interaction effects of N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide (PP13TFSI) ionic liquid (as plasticizer) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) on PVDF-HFP polymer remain unclear. In this work, the molecular structure of ionic liquid gel polymer electrolyte (ILGPE) composed of PP13TFSI, LiTFSI and PVDF-HFP was studied by Raman spectroscopy and Fourier-transform infrared spectroscopy (FTIR). Meanwhile, X-ray diffraction (XRD) analysis was performed to qualify the crystallization of PVDF-HFP polymer in the ILGPE with or without PP13TFSI or/and LiTFSI to investigate ionic liquid or/and LiTFSI impact on PVDF-HFP polymer. The results showed that PP13TFSI, LiTFSI and PVDF-HFP were physical-blending without chemical reaction, but with molecular coordination with PVDF-HFP polymer chain. In addition, the crystallization of PVDF-HFP could be changed by additions of PP13TFSI and LiTFSI at the same time, and the ionic conductivity could be improved with increasing amorphous phase in polymer matrix. The electrochemical stability window and thermal stability of ILGPE became worse with the N-methyl-2-pyrrolidone (NMP) residue inside the ILGPE. The LiFePO4/Li battery with the optimized ILGPE (the weight ratio of ionic liquid, LiTFSI, and PVDF-HFP polymer was 3/1/1) showed a good C-rate capability at room temperature. In summary, PP13TFSI and LiTFSI could coordinate with PVDF-HFP polymer chain, and no chemical reaction took place among the three compounds during preparing ILGPE. Furthermore, it is necessary to remove NMP solvent from ILGPE during drying process to improve the electrochemical stability window and thermal stability of ILGPE.

Graphical Abstract


ionic liquid gel polymer electrolyte, electrochemical stability, thermal stability

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[1] Ai X P( 艾新平), Gao Y L( 曹余良), Yang H X( 杨汉西). Self-activating safety mechanisms for Li-ion batteries[J]. Journal of Electrochemistryl( 电化学), 2010,16(1):6-10.

[2] Chen D Q( 陈丁琼), Yang Y( 杨阳), Li Q L( 李秋丽), et al. Research progresses in Si-based anode materials for lithium-ion batteries[J]. Journal of Electrochemistryl( 电化学), 2011,22(5):489-488.

[3] Yang Y( 杨勇). 锂离子电池的发现与发展-兼谈电池材料与固态电化学[J]. Journal of Electrochemistryl( 电化学), 2019,25(5):614-615.

[4] Gu Y R( 顾月茹), Zhao W M( 赵卫民), Su C H( 苏长虎), et al. Reaearch progress in improvement for low temperature performance of lithium-ion batteries[J]. Journal of Electrochemistryl( 电化学), 2018,24(5):488-496.

[5] Sheng O W, Jin C B, Luo J M, et al. Mg2B2O5 nanowire enabled multifunctional solid-state electrolytes with high ionic conductivity, excellent mechanical properties, and flame-retardant performance[J]. Nano Letters, 2018,18(5):3104-3122.
URL pmid: 29692176

[6] Park K, Yu B C, Goodenough J B. Electrochemical and chemical properties of Na2NiO2 as a cathode additive for a rechargeable sodium battery[J]. Chemistry of Materials, 2015,27(19):6682-6688.

[7] Yi J, Liu X Z, Guo S H, et al. Novel stable gel polymer electrolyte?: toward a high safety and long life Li-air battery[J]. ACS Applied Materials and Interface. 2015,42(7):23798-23804.

[8] Pan X N, Liu T Y, Kauz D J, et al. High-performance N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide/poly(vinylidene fluoride-hexafluoropropylene) gel polymer electrolytes for lithium metal batteries[J]. Journal of Power Sources, 2018,403:127-136.
doi: 10.1016/j.jpowsour.2018.09.080 URL

[9] Raji A R O, Salvatierra R V, Kim N D, et al. Lithium batteries with nearly maximum metal storage[J]. ACS Nano, 2017,11:6362-6369.
URL pmid: 28511004

[10] Stich M, Göttlinger M, Kurniawan M, et al. Hydrolysis of LiPF6 in carbonate-based electrolytes for lithium-ion batteries and in aqueous media[J]. Journal of Physical Chemistry C, 2018,122(16):8836-8842.

[11] Kawamura T, Kimura A, Egashira M, et al. Thermal stability of alkyl carbonate mixed-solvent electrolytes for lithium ion cells[J]. Journal of Power Sources, 2002,104(2):260-264.

[12] Hu G X( 胡广侠), Xie J Y( 解晶莹). Some consideration for lithium-ion cells safety[J]. Journal of Electrochemistryl( 电化学), 2002,8(3):245-251.

[13] Chen Y H( 陈玉红), Tang Z Y( 唐致远), He Y B( 贺艳兵), et al. Research of explosion mechanism of lithium-ion battery[J]. Journal of Electrochemistryl( 电化学). 2006,12(3):266-270.

[14] Yang N C( 杨纳川), Wang Y( 王玉), Shuai Y( 帅毅), Chen K H( 陈康华). Research on preparation and properties of low cost sulfide solid electrolytes Li6-xPS5-xClx[J]. Journal of Electrochemistryl( 电化学), DOI: 10.13208/j.electrochem.190715.

[15] Cheng H( 程琥), Nie X Y( 聂晓燕), Shen Y D( 申叶丹). Performance of piperidine ionic liquid based mixed electrolyte in Li/LiCoO2 cell[J]. Journal of Electrochemistryl( 电化学), 2017,23(1):59-63.

[16] Jin Y D, Zhang J H, Song J Z, et al. Functionalized ionic liquids based on quaternary ammonium cations with two ether groups as new electrolytes for Li/LiFePO4 secondary battery[J]. Journal of Power Sources, 2014,254:137-147.
doi: 10.1016/j.jpowsour.2013.12.048 URL

[17] Liu Z D, Feng Y, Li W L. High dielectric constant and low loss of polymeric dielectric composites filled by carbon nanotubes adhering BaTiO3 hybrid particles[J]. RSC Advances, 2015,5(37):29017-29021.
doi: 10.1039/C5RA00639B URL

[18] Wang W, Alexandridis P. Composite polymer electrolytes: nanoparticles affect structure and properties[J]. Polymers, 2016, 8(11): UNSP 387.
doi: 10.3390/polym8110387 URL pmid: 30974666

[19] Zhang X Y, Yang L, Hao F, et al. Lithium-excess research of cathode material Li2MnTiO4 for lithium-ion batteries[J]. Nanomater, 2015,5(4):1985-1994.
doi: 10.3390/nano5041985 URL

[20] Wang C, Zhang H R, Li J D, et al. The interfacial evolution between polycarbonate-based polymer electrolyte and Li-metal anode[J]. Journal of Power Sources, 2018,397:157-161.

[21] Song A M, Huang Y, Zhong X P, et al. Gel polymer electrolyte with high performances based on pure natural polymer matrix of potato starch composite lignocellulose[J]. Electrochimica Acta, 2017,245:981-992.



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