Ion-Selective Polyamide Acid Nanofiber Separators for High-Rate and Stable Lithium–Sulfur Batteries

• DOI: 10.1021/acsami.8b10795
• Publication Date: 2018-10-30T18:05:06Z
• Authors: Xiang Luo; Xianbo Lu; Gangyong Zhou; Xingyu Zhao; Yue Ouyang; Xiaobo Zhu; Yue-E Miao; Tianxi Liu
• Keywords: separator; 2500 Materials Science; electrospun nanofibers; ion selective; lithium-sulfur battery; 02 engineering and technology; 540; 0210 nano-technology; 7. Clean energy; dual functions

Lithium-sulfur (Li-S) batteries have attracted great attention because of their high energy density and theoretical capacity. However, the "shuttle effect" caused by dissolution polysulfides in liquid electrolytes severely hinders practical applications. Herein, we originally propose a carboxyl functional polyamide acid (PAA) nanofiber separator with dual functions for inhibiting polysulfide transfer promoting Li+ migration via one-step electrospinning synthesis method. Especially, groups -COOH PAA separators provide an electronegative environment, which promotes transport but suppresses negative anions. Therefore, can act as efficient electrostatic shield to restrict on cathode side, while efficiently across separator. As result, ultralow decay rate only 0.12% per cycle is achieved after 200 cycles at 0.2 C, less than half that (0.26% cycle) commercial Celgard