Luo Lin, Ma Kang, Song Xin, Zhao Yuling, Tang Jie, Zheng Zongmin, Zhang Jianmin
College of Mechanical and Electrical Engineering, National Engineering Research Center for Intelligent Electrical Vehicle Power System (Qingdao), Qingdao University, Qingdao 266071, China.
State Key Laboratory of Bio Fibers and Eco Textiles, Qingdao University, No. 308 Ningxia Road, Qingdao 266071, China.
Polymers (Basel). 2023 Oct 17;15(20):4120. doi: 10.3390/polym15204120.
Simultaneously high-rate and high-safety lithium-ion batteries (LIBs) have long been the research focus in both academia and industry. In this study, a multifunctional composite membrane fabricated by incorporating poly(vinylidene fluoride) (PVDF) with magnesium carbonate hydroxide (MCH) nanofibers was reported for the first time. Compared to commercial polypropylene (PP) membranes and neat PVDF membranes, the composite membrane exhibits various excellent properties, including higher porosity (85.9%) and electrolyte wettability (539.8%), better ionic conductivity (1.4 mS·cm), and lower interfacial resistance (93.3 Ω). It can remain dimensionally stable up to 180 °C, preventing LIBs from fast internal short-circuiting at the beginning of a thermal runaway situation. When a coin cell assembled with this composite membrane was tested at a high temperature (100 °C), it showed superior charge-discharge performance across 100 cycles. Furthermore, this composite membrane demonstrated greatly improved flame retardancy compared with PP and PVDF membranes. We anticipate that this multifunctional membrane will be a promising separator candidate for next-generation LIBs and other energy storage devices, in order to meet rate and safety requirements.
同时具备高倍率和高安全性的锂离子电池（LIBs）长期以来一直是学术界和工业界的研究重点。在本研究中，首次报道了一种通过将聚偏氟乙烯（PVDF）与氢氧化镁碳酸酯（MCH）纳米纤维复合制备的多功能复合膜。与商用聚丙烯（PP）膜和纯PVDF膜相比，该复合膜具有多种优异性能，包括更高的孔隙率（85.9%）和电解质润湿性（539.8%）、更好的离子电导率（1.4 mS·cm）以及更低的界面电阻（93.3 Ω）。它在高达180 °C时仍能保持尺寸稳定，可防止锂离子电池在热失控初期发生快速内部短路。当用这种复合膜组装的硬币电池在高温（100 °C）下进行测试时，它在100个循环中表现出优异的充放电性能。此外，与PP膜和PVDF膜相比，这种复合膜的阻燃性有了极大提高。我们预计，这种多功能膜将成为下一代锂离子电池和其他储能设备的有前途的隔膜候选材料，以满足倍率和安全要求。
