熔体mLLDPE静电纺纤维基锂电池隔膜的制备

Preparation of Lithium Battery Separator Based on Melt-Electrospun mLLDPE Fibers

采用熔体静电纺丝方法制备了茂金属线性低密度聚乙烯（mLLDPE）无纺纤维，并与聚偏氟乙烯（PVDF）溶液静电纺纳米纤维复合改性，成功制备出mLLDPE无纺纤维基锂电池隔膜。对该锂电池隔膜的孔隙率、热稳定性、充放电性能测试结果表明，该隔膜的孔隙率在54％～62％，首次放电比容量为70mA·h／g，且循环稳定性良好，性能优于同等测试条件下的商业锂电池隔膜，可以应用于锂电池。

mLLDPE non-woven fibers were successfully prepared via melt electrospinning. However, the fibers are thick, and the pores size of membrane made from mLLDPE non-woven fibers is large, so mLLDPE non-woven fibers cannot be directly used as lithium battery separator. Electrospun PVDF nanofibers and the melt-electrospun mLLDPE fibers were combined to form a new compounding membrane, which was successfully applied as lithium battery separator. The porosity rate, thermal stability and charge and discharge properties were characterized. The results show that the porosity rate of the composite separator is 54 % -- 62 % and the first specific discharge capacity is 70 mA. h/g with a good cyclic performance. The performance of this compounding membrane is superior to the commercial lithium separator under the same test condition.