Lithium-ion batteries (LIBs) play a critical role in modern portable electronic devices, electric vehicles, and wearable electronics. However, the formation of lithium dendrites during cycling results in serious capacity loss and safety risks owing to the heterogeneous transport and deposition of Li. In this work, we present a poly(vinylidene fluoride) (PVDF)-based composite membrane with a continuous metal–organic framework (MOF) layer as high-performance separators in LIBs. The PVDF membranes with uniform pore structures are prepared by using superspreading strategy, facilitating the growth of continuous and controllable MOF layer inside the membranes via a simple interfacial synthesis. The as prepared PVDF-MOF composite membranes display uniform and continuous subnanochannels with connected opened metal sites (OMS), which can generate a homogeneous transport of Li. Taking advantages of the low impedance (∼2 Ω), high ionic conductivity (0.61 mS cm), and high stripping peak current (0.89 mA cm), the PVDF-MOF composite separators efficiently prevent the uneven deposition and the generation of lithium dendrites. Moreover, the PVDF-MOF-based LIBs showed a high capacity retention rate of 81.0 % after 250 cycles. This strategy paves a new avenue for MOF-based composite separator in LIBs.

中文翻译：

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用于高性能锂离子电池隔膜的具有连续金属有机骨架层的聚偏二氟乙烯基复合膜

锂离子电池 (LIB) 在现代便携式电子设备、电动汽车和可穿戴电子产品中发挥着至关重要的作用。然而，由于锂的异质传输和沉积，循环过程中锂枝晶的形成会导致严重的容量损失和安全风险。在这项工作中，我们提出了一种基于聚偏二氟乙烯（PVDF）的复合膜，具有连续的金属有机骨架（MOF）层，作为LIB中的高性能隔膜。采用超铺展策略制备了具有均匀孔结构的PVDF膜，通过简单的界面合成促进膜内连续且可控的MOF层的生长。所制备的PVDF-MOF复合膜显示出均匀且连续的亚纳米通道，并具有连接的开放金属位点（OMS），可以产生Li的均匀传输。 PVDF-MOF复合隔膜利用低阻抗（∼2 Ω）、高离子电导率（0.61 mS cm）和高剥离峰值电流（0.89 mA cm）的优点，有效防止不均匀沉积和锂枝晶的生成。此外，基于PVDF-MOF的LIB在250次循环后表现出高达81.0%的容量保持率。这一策略为锂离子电池中基于 MOF 的复合隔膜开辟了一条新途径。