Structure–Performance Relationships of Li-Ion Battery Fiber-Based Separators
Structure–Performance Relationships of Li-Ion Battery Fiber-Based Separators
复制标题
锂离子电池纤维隔膜的结构与性能关系
DOI：
10.1021/acsapm.2c00216
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发表时间：
2022
影响因子：
5
通讯作者：
Fedkiw, Peter S.
中科院分区：
文献类型：
--
作者：
Luiso, Salvatore;Petrecca, Michael J.;Williams, Austin H.;Christopher, Jerush;Velev, Orlin D.;Pourdeyhimi, Behnam;Fedkiw, Peter S.
锂离子电池隔膜正受到科学界越来越多的关注。许多研究工作倾向于制造具有小而均匀的孔径的高性能纤维基电池隔板，以最大化离子电导率和电池放电容量。在这里，我们表明，不仅孔径，而且孔径分布有这些电化学性能的重要影响。在这项工作中，我们研究了非织造膜从一个单一的聚合物，聚（偏二氟乙烯）（PVDF），具有不同的孔径和孔径分布，使用三种不同的技术（熔喷，静电纺丝和剪切纺丝）。我们评估了它们作为锂离子电池隔膜的性能。虽然熔喷通常用于生产商业微纤维/纳米纤维，但电纺丝主要在学术文献中进行研究。剪切纺丝是一种新兴的方法来制造纳米纤维材料，其中，对于本研究，所得PVDF膜的形态可以从纤维状控制到纳米片状，随后对电化学性能产生影响。我们发现，孔径越小，孔径分布越宽，电解质的吸收和离子电导率的垫，从而提高在使用中的放电容量和倍率性能的Li/LiCoO 2电池。
Lithium-ion battery separators are receiving increased consideration from the scientific community. Many research efforts trend toward creating high-performance fiber-based battery separators with a small and uniform pore size to maximize ionic conductivity and cell discharge capacity. Here, we show that not only the pore size but also the pore size distribution has an important effect on these electrochemical properties. In this work, we studied nonwoven membranes fabricated from a single polymer, poly(vinylidene fluoride) (PVDF), with different pore sizes and pore size distributions using three different techniques (meltblowing, electrospinning, and shear spinning). We evaluate their performance as separators in Li-ion cells. Although meltblowing is commonly employed to produce commercial microfibers/nanofibers, electrospinning has been studied mostly in the academic literature. Shear spinning is an emerging method to fabricate nanofibrous material where, for this study, the morphology of the resulting PVDF membranes may be controlled from fibrous-like to nano-sheet-like with subsequent effects on the electrochemical properties. We show that the smaller the pore size and the wider the pore size distribution, the higher are the electrolyte uptake and ionic conductivity of the mats, resulting in improved in-use discharge capacity and rate capability of Li/LiCoO2cells.