Iron Single Atoms-Anchored Hollow Porous Carbon Spheres of Brain Fold-like Surfaces Composited with Manganese Dioxide Nanowires as an Advanced Sulfur Host for Lithium–Sulfur Batteries

Abstract

Design of sulfur hosts for effective suppression of shuttling of lithium polysulfides (LiPS) is critical to achieving high-performance lithium–sulfur batteries (LSBs). Here, iron single atoms (SA(Fe))-decorated hollow porous carbon spheres (HPCS) composited with α-MnO₂ nanowires are fabricated as a high-performance sulfur host for LSBs. This composite sulfur host takes advantage of Fe SAs to accelerate conversion reactions of LiPS, α-MnO₂ nanowires to adsorb LiPS, and HPCS to boost charge transport and to confine LiPS, enabling high performance of LSBs. The HPCS@SA(Fe)/α-MnO₂-based LSB exhibits a high initial specific capacity of 1095 mAh g^–1 at 0.1C and maintains a decent specific capacity of 343 mAh g^–1 at 2C. A high capacity retention rate of 81.3% after a 300 cycle operation at 1C is achieved, corresponding to a low average capacity decay rate of 0.062% per cycle. Construction of composite sulfur hosts, synergizing unique shuttling suppression functionalities of multiple constituent components, proves to be a promising strategy for development of advanced LSBs.