Permselective\nIonic-Shield for High-Performance Lithium–Sulfur\nBatteries

Abstract

Lithium–sulfur batteries (LiSBs)\nare promising\nnext-generation\nbatteries because of their low cost and high theoretical energy densities.\nDespite remarkable advances over the decades, polysulfide (PS) shuttling\nduring battery cycling remains a challenge in the development of commercial\nLiSBs and is accelerated under practical conditions. Herein, we report\na permselective ionic shield between the electrodes that blocks PS\nshuttles and passes Li ions to high-performance LiSBs. This shield\nis easily built onto the separator by ionic complexation and intermolecular\nbonding of functional polymers, thereby improving the battery performance\nand safety. The LiSB with the developed shield delivers a remarkable\ndischarge capacity of 917 mAh g^–1 after 1000 cycles\nat 2 C. In addition, the behavior of LiSBs under practical conditions\nthat can realize a high energy density is investigated to achieve\nthe optimal balance in this system. This study provides new insights\ninto the imminent development of separators for practical LiSBs.