Tang Liping, Lei Zhiqiang, Wu Yankang, Chen Jian, Jiao Wei
Department of Materials Science and Engineering, Sichuan University of Science and Engineering, 643000 Zigong, Sichuan, P. R. China.
Sichuan Province Key Laboratory for Corrosion and Protection of Material, Sichuan University of Science and Engineering, 643000 Zigong, Sichuan, P. R. China.
Langmuir. 2023 Sep 26;39(38):13459-13465. doi: 10.1021/acs.langmuir.3c01121. Epub 2023 Sep 13.
As an important component, the properties of separators directly affect the capacity, life, and safety performance of lithium-ion batteries (LIBs). The high thermal stability and safety application value of the thermoplastic elastomer poly(styrene--isoprene--styrene) block copolymer (SIS) with different block ratios were explored to enhance the thermal stability and mechanical strength of the cross-linked polyacrylonitrile (PAN) membranes by vulcanization cross-linking and heat treatment. Among these membranes, the sample named the S/PAN/SIS-4019 separator was confirmed to be a self-closing separator that can cope with the thermal runaway, attributing to the continued fusion of the SIS soft and hard segments in the cross-linked structure under high-temperature heat treatment. Moreover, the tensile strength of S/PAN/SIS-4019 separator increased to 17.49 MPa, which was better than that of Celgard 2400, PAN, and other inlay separators. Using S/PAN/SIS-4019 as a battery separator, lithium-ion batteries showed a superior electrochemical performance compared to the usage of Celgard 2400. Owing to the stable pore structure and thermally protected self-shutdown mechanism, the overall properties of the obtained cross-linked separator were improved in terms of higher thermal stability, high ionic conductivity, and electrochemical properties.
作为一个重要组成部分，隔膜的性能直接影响锂离子电池（LIBs）的容量、寿命和安全性能。通过硫化交联和热处理，探索了具有不同嵌段比例的热塑性弹性体聚（苯乙烯-异戊二烯-苯乙烯）嵌段共聚物（SIS）的高热稳定性和安全应用价值，以提高交联聚丙烯腈（PAN）膜的热稳定性和机械强度。在这些膜中，名为S/PAN/SIS-4019隔膜的样品被确认为一种能够应对热失控的自关闭隔膜，这归因于高温热处理下交联结构中SIS软硬段的持续融合。此外，S/PAN/SIS-4019隔膜的拉伸强度提高到了17.49MPa，优于Celgard 2400、PAN和其他镶嵌隔膜。使用S/PAN/SIS-4019作为电池隔膜时，锂离子电池相比使用Celgard 2400表现出更优异的电化学性能。由于稳定的孔结构和热保护自关闭机制，所得交联隔膜的整体性能在更高的热稳定性、高离子电导率和电化学性能方面得到了改善。
