Revealing the Synergistic Effect of Core‐Shell Structure MoSe ₂ @MoO ₃ as Highly Efficient Cathode for Robust Lithium‐Sulfur Batteries

ABSTRACT Lithium‐sulfur batteries (LSBs) imply a promising replacement for conventional lithium‐ion batteries owing to their outstanding theoretical energy density. Nevertheless, the migration of intermediate polysulfide (LiPS) species can decrease sulfur utilization, cause anode corrosion, and restrict the long‐term cycling of LSBs. This limitation is associated with the LiPS trapping ability and catalytic conversion reaction capability of the sulfur cathode. Consequently, it is crucial to design a suitable sulfur host that can efficiently confine LiPS and promote the transformation reaction. In this work, a heterogeneous nanostructure of MoSe ₂ @MoO ₃ is fabricated and utilized as a sulfur cathode for high‐performance LSBs. The combined effects of MoSe ₂ , with superior catalytic activity, and MoO ₃ , with strong adsorption capacity, not only enhance sulfur utilization but also effectively suppress the shuttling effect. As a result, the MoSe ₂ @MoO ₃ /S cathode delivered an outstanding initial capacity of 1268 mAh g ⁻¹ at 0.1 C and maintained a high specific capacity of 432 mAh g ⁻¹ even at a high‐rate of 5 C. Notably, batteries employing the MoSe ₂ @MoO ₃ /S cathode demonstrated exceptional long‐term cycling stability, achieving a capacity retention of 70.7% after 1000 charge/discharge cycles at 1 C.