Traditional polyolefin separators used in lithium-ion batteries (LIBs) suffer from poor wettability with electrolytes, significantly hindering their application in high-energy density batteries. To address this issue, we developed an EVOH-coated polyethylene separator using a phase separation method. The modified separator retains mechanical properties such as tensile strength and puncture resistance similar to the base separator. The soft EVOH coating enhances the separator’s ability to conform to the electrode under stress, improving contact and overall battery performance. Notably, the EVOH coating significantly enhances the separator’s electrolyte wettability, resulting in an electrolyte uptake of 253%. The abundant hydroxyl groups within the coating improve the electrochemical performance, leading to enhanced discharge rate capacity and cycling stability. The lithium-ion transference number of the modified separator increased to 0.76. The straightforward preparation method and superior performance of the EVOH-coated separator suggest its promising application in high-performance LIBs.

中文翻译：

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用于高性能锂离子电池的新型 EVOH 涂层聚乙烯隔膜


用于锂离子电池 （LIB） 的传统聚烯烃隔膜与电解质的润湿性差，严重阻碍了它们在高能量密度电池中的应用。为了解决这个问题，我们开发了一种使用相分离法的 EVOH 涂层聚乙烯隔膜。改性隔膜保持了与基础隔膜相似的机械性能，例如拉伸强度和抗穿刺性。柔软的 EVOH 涂层增强了隔膜在压力下与电极相适应的能力，从而改善了接触和整体电池性能。值得注意的是，EVOH 涂层显著提高了隔膜的电解液润湿性，使电解液吸收率达到 253%。涂层中丰富的羟基改善了电化学性能，从而提高了放电速率容量和循环稳定性。改性隔膜的锂离子转移数增加到 0.76。EVOH 涂层隔膜的简单制备方法和卓越的性能表明其在高性能 LIB 中的应用前景广阔。