A lithium ethylene-vinyl alcohol copolymer sulfate (EVOH-SO3Li)/polyimide (PI) composite fiber membrane prepared via high-voltage electrospinning and impregnation was used as a lithium-ion battery separator for research purposes. The polyamic acid spinning solution was synthesized from 3,3′′,4,4′′-benzophenone tetracarboxylic dianhydride and 4,4-diaminodiphenyl ether. The PI fiber membrane was prepared via high-voltage electrospinning and thermal imidization, and EVOH-SO3Li was then coated on the surface of the PI fiber to prepare an EVOH-SO3Li/PI composite fiber membrane material (t-EVOH-SO3Li/PI). Overall, the EVOH-SO3Li/PI membrane exhibits excellent basic physical properties, given the clear three-dimensional network microstructure. When compared with EVOH-SO3Li/PI composite fiber membrane prepared via the cospinning method (s-EVOH-SO3Li/PI), its electrolyte uptake and tensile strength can increase to 739% and 17.56 MPa, respectively. Additionally, the EVOH-SO3Li/PI composite fiber membrane prepared via high-voltage electrospinning and impregnation exhibits better heat shrinkage stability, electrochemical performance, and high-temperature self-closing pores function. The electrochemical stability window, electrochemical impedance, and ionic conductivity correspond to 5.8 V, 310 Ω, and 3.753 × 10−3 S cm−1, respectively. Specifically, at 200°C, the internal pores can close effectively, and this is extremely important for the safety of lithium-ion batteries.

中文翻译：

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自闭孔耐高温EVOH-SO3Li/PI纤维膜的制备及应用

通过高压静电纺丝和浸渍制备的锂乙烯-乙烯醇共聚物硫酸盐（EVOH-SO3Li）/聚酰亚胺（PI）复合纤维膜用作锂离子电池隔膜用于研究目的。聚酰胺酸纺丝液由3,3'',4,4''-二苯甲酮四甲酸二酐和4,4-二氨基二苯醚合成。通过高压静电纺丝和热酰亚胺化制备PI纤维膜，然后将EVOH-SO3Li包覆在PI纤维表面，制备EVOH-SO3Li/PI复合纤维膜材料（t-EVOH-SO3Li/PI） . 总体而言，EVOH-SO3Li/PI 膜表现出优异的基本物理性能，具有清晰的三维网络微观结构。与共纺法制备的EVOH-SO3Li/PI复合纤维膜（s-EVOH-SO3Li/PI）相比，其电解质吸收和拉伸强度可分别增加到 739% 和 17.56 MPa。此外，通过高压静电纺丝和浸渍制备的EVOH-SO3Li/PI复合纤维膜具有更好的热收缩稳定性、电化学性能和高温自闭孔功能。电化学稳定性窗口、电化学阻抗和离子电导率分别对应于 5.8 V、310 Ω 和 3.753 × 10-3 S cm-1。具体来说，在 200°C 时，内部孔隙可以有效闭合，这对锂离子电池的安全性至关重要。通过高压静电纺丝和浸渍制备的EVOH-SO3Li/PI复合纤维膜具有更好的热收缩稳定性、电化学性能和高温自闭孔功能。电化学稳定性窗口、电化学阻抗和离子电导率分别对应于 5.8 V、310 Ω 和 3.753 × 10−3 S cm−1。具体来说，在 200°C 时，内部孔隙可以有效闭合，这对锂离子电池的安全性至关重要。通过高压静电纺丝和浸渍制备的EVOH-SO3Li/PI复合纤维膜具有更好的热收缩稳定性、电化学性能和高温自闭孔功能。电化学稳定性窗口、电化学阻抗和离子电导率分别对应于 5.8 V、310 Ω 和 3.753 × 10-3 S cm-1。具体来说，在 200°C 时，内部孔隙可以有效闭合，这对锂离子电池的安全性至关重要。