An Electronegative Modified Separator with Semifused Pores as a Selective Barrier for Highly Stable Lithium–Sulfur Batteries

• Published in: Industrial & engineering chemistry research Vol. 58; no. 31; pp. 14538 - 14547
• Main Authors: Wang, Junxiao, Li, Mengjia, Liu, Chong, Liu, Yong, Zhao, Tongkun, Zhai, Pengfei, Wang, Jingtao
• Format: Journal Article
• Language: English
• Published: American Chemical Society 07.08.2019
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/acs.iecr.9b01727

The rapid capacity fading and poor cycling life caused by polysulfide shuttle severely limit the development of high-energy-density lithium–sulfur batteries. Herein, a new type of electronegative modified separator with semifused pores is designed to suppress polysulfide shuttle and simultaneously elevate Li+ conduction. This separator is facilely prepared by lithiation of Nafion/poly­(acrylic acid) electrospun fiber mat on a commercial separator. Abundant electronegative groups on the separator strongly repel anionic polysulfides, effectively inhibiting the shuttle effect. Moreover, these groups provide numerous sites for Li+ transfer, and meanwhile the semifused pores work as low-barrier transport pathways, jointly facilitating Li+ conduction. Therefore, the battery exhibits outstanding cycling stability (decay rate of 0.023% per cycle during 1000 cycles at 1.0 C) and decent rate capability (discharge capacity of 730 mAh g–1 even at 3.0 C). Additionally, the sulfonated poly­(ether ether ketone) is taken as an example to verify the universality of this design strategy.