Efficient Sulfur Host Based on Yolk‐Shell Iron Oxide/Sulfide‐Carbon Nanospindles for Lithium‐Sulfur Batteries

Abstract

Abstract Numerous nanostructured materials have been reported as efficient sulfur hosts to suppress the problematic “shuttling” of lithium polysulfides (LiPSs) in lithium‐sulfur (Li−S) batteries. However, direct comparison of these materials in their efficiency of suppressing LiPSs shuttling is challenging, owing to the structural and morphological differences between individual materials. This study introduces a simple route to synthesize a series of sulfur host materials with the same yolk‐shell nanospindle morphology but tunable compositions (Fe3O4, FeS, or FeS2), which allows for a systematic investigation into the specific effect of chemical composition on the electrochemical performances of Li−S batteries. Among them, the S/FeS2−C electrode exhibits the best performance and delivers an initial capacity of 877.6\u2005mAh\u2009g−1 at 0.5\u2005C with a retention ratio of 86.7\u2009% after 350\u2005cycles. This approach can also be extended to the optimization of materials for other functionalities and applications.