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

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 mAh g 1 at 0.5 C with a retention ratio of 86.7 after 350 cycles. This approach can also be extended to the optimization of materials for other functionalities and application