Boosting Adsorption and Catalysis of Polysulfides by Multifunctional Separator for Lithium–Sulfur Batteries

Abstract

Lithium–sulfur (Li–S) batteries are considered promising energy storage technologies due to their high energy density and environmental friendliness. However, the unsatisfactory electrochemical performance mainly caused by dissolution and shuttling of polysulfides limits their application. Herein, a multifunctional separator, i.e., the sodium alginate (SA) fiber membrane with in situ loading of ZIF-67 attached on the polyacrylonitrile (PAN) matrix (ZIF-67/SA-PAN), is developed for Li–S batteries. On the basis of the synergistic adsorption and catalytic effect, ZIF-67/SA-PAN can inhibit the shuttling of polysulfides and promote fast transformation of the intercepted polysulfides, as revealed by in situ characterization and theoretical calculations. The ZIF-67/SA-PAN separator endows Li–S batteries with high reversible capacity (e.g., 797.4 mAh g–1 with a high sulfur loading of 5.45 mg cm–2 at 0.1 C) and long cycle life (500 cycles at 1 C). The ZIF-67/SA-PAN functional separator in this work can provide a facile and inexpensive approach to fabricate practical Li–S batteries.