A zinc coordination supramolecular network synergized manganese dioxide achieves high-rate lithium–sulfur batteries

Abstract

Lithium–sulfur batteries (LSBs) have attracted considerable attention due to their high capacity and energy density, however, the electrochemical performance of LSBs was limited by the difficult conversion of lithium polysulfides (LiPSs). Coordination supramolecular networks (CSNs) have flexible structures, abundant active sites, and intermolecular interactions, which can facilitate the transformation of LiPSs and ion/charge transport. Herein, we combined a zinc coordination supramolecular network (Zn-CSN) with MnO₂ to synthesize Zn-CSN@MnO₂via a one-pot method. Zn-CSN@MnO₂ accelerates the evolution of LiPSs and promotes the migration of lithium ions. Zn-CSN@MnO₂ as a sulfur host in LSBs displays outstanding rate performance (406.55 mAh g⁻¹ at 4C). It has a high initial specific capacity of 1027.89 mAh g⁻¹ at 0.5C, cycling 150 cycles with a capacity loss of 0.2% per cycle. Surprisingly, it runs 400 cycles at a high current density of 5C with a capacity retention of 80.5%. This synergistic strategy for CSNs and oxides has brightened the prospects of the practical applications of LSBs.