Barbosa J C, Correia D M, Gonçalves R, de Zea Bermudez V, Silva M M, Lanceros-Mendez S, Costa C M
Center of Physics, University of Minho, 4710-058 Braga, Portugal; Department of Chemistry and CQ-VR, University of Trás -os -Montes e Alto Douro, 5000-801 Vila Real, Portugal.
Center of Chemistry, University of Minho, 4710-058 Braga, Portugal.
J Colloid Interface Sci. 2021 Jan 15;582(Pt A):376-386. doi: 10.1016/j.jcis.2020.08.046. Epub 2020 Aug 17.
Electrospun poly(vinylidene fluoride) (PVDF) fiber membranes doped with different ionic liquids (ILs) and sharing the same anion were produced and their potential as separator membranes for battery applications was evaluated. Different types of ILs containing the same anion, bis(trifluoromethylsulfonyl)imide [TFSI], were used with IL concentrations ranging between 0 and 15 wt% The morphology, microstructure, thermal and electrical properties (ionic conductivity and electrochemical window) of the membranes were evaluated. The presence of ILs in the PVDF polymer matrix influences the fiber diameter and the content of the polar β phase within the polymer, as well as the degree of crystallinity. The thermal stability of the membranes decreases with the incorporation of IL. Impedance spectroscopy tests show a maximum ionic conductivity of 2.8 mS.cm for 15% of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][TFSI]) at room temperature. The electrochemical stability of the samples ranges from 0.0 to 6.0 V. When evaluated as battery separator membranes in C-LiFePO half-cells, a maximum discharge capacity of 119 mAh.g at C-rate was obtained for the PVDF membrane with 15% [Emim][TFSI], with a coulombic efficiency close to 100%. The results demonstrate that the produced electrospun membranes are suitable for applications as separators for lithium ion batteries (LIBs).
制备了掺杂不同离子液体（ILs）且具有相同阴离子的静电纺聚偏氟乙烯（PVDF）纤维膜，并评估了它们作为电池应用隔膜的潜力。使用了含有相同阴离子双（三氟甲基磺酰）亚胺[TFSI]的不同类型离子液体，离子液体浓度范围为0至15 wt%。对膜的形态、微观结构、热性能和电性能（离子电导率和电化学窗口）进行了评估。PVDF聚合物基体中离子液体的存在会影响纤维直径、聚合物中极性β相的含量以及结晶度。随着离子液体的加入，膜的热稳定性降低。阻抗谱测试表明，在室温下，15%的1-乙基-3-甲基咪唑双（三氟甲基磺酰）亚胺（[Emim][TFSI]）的最大离子电导率为2.8 mS·cm。样品的电化学稳定性范围为0.0至6.0 V。当在C-LiFePO4半电池中作为电池隔膜进行评估时，含15%[Emim][TFSI]的PVDF膜在C倍率下的最大放电容量为119 mAh·g，库仑效率接近100%。结果表明，所制备的静电纺膜适用于锂离子电池（LIBs）隔膜应用。
