The fabrication of novel separators with high safety and remarkable performance has always been a hot topic due to their effect on the safety and electrochemical performance of lithium-ion batteries (LIBs). In this study, the impregnation method is used to create the 4, 4′-diphenylmethane diisocyanate (MDI) modified poly (m-phenylene isophthalamide) (PMIA) separators (PMIA-M) with 3-D sponge-like porous network structure. With the increase of cross-linking time, the elongation at break of PMIA-M separators increases to 47.2%, and the mechanical strength decreases after increasing to 31.7 MPa. In addition, PMIA-M separators has excellent thermal stability, no dimensional shrinkage at 200 °C and self-extinguishing property. Moreover, the expansion of polar groups improves the surface polarity of the PMIA-M separators, promoting the electrolyte-philic property and leading to a significant increase in electrochemical performance. Transport channels of Li⁺ can be regulated, so that the growth of lithium dendrites can be inhibited and the cycle stability is significantly improved. The capacity retention of the LiCoO₂/Li cell assembled by the PMIA-M-12 separator is 94.7% after 50 cycles at 0.2C and prior to that of the pristine PMIA separator (77.6%). Therefore, the PMIA-M separators are promising material for electronic products and new energy vehicles.

由于其对锂离子电池（LIB）的安全性和电化学性能的影响，制造具有高安全性和卓越性能的新型隔膜一直是热门话题。在这项研究中，浸渍法用于制备具有 3-D 海绵状多孔网络结构的 4, 4'-二苯基甲烷二异氰酸酯 (MDI) 改性聚间苯二甲酰间苯二胺 (PMIA) 隔膜 (PMIA-M)。随着交联时间的增加，PMIA-M隔膜的断裂伸长率增加到47.2%，机械强度增加到31.7 MPa后有所下降。此外，PMIA-M隔膜还具有优异的热稳定性，在200℃时尺寸不收缩，具有自熄性。此外，极性基团的扩展提高了 PMIA-M 隔膜的表面极性，促进亲电解质特性并导致电化学性能显着提高。李的运输渠道⁺可以调节，从而抑制锂枝晶的生长，循环稳定性显着提高。由 PMIA-M-12 隔膜组装的LiCoO ₂ /Li 电池在 0.2C 下循环 50 次后的容量保持率为 94.7%，高于原始 PMIA 隔膜的容量保持率 (77.6%)。因此，PMIA-M隔膜是很有前途的电子产品和新能源汽车材料。