Revealing the Synergistic Effect of Core-Shell Structure MoSe₂@MoO₃ as Highly Efficient Cathode for Robust Lithium-Sulfur Batteries

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 MoSe₂@MoO₃ is fabricated and utilized as a sulfur cathode for high-performance LSBs. The combined effects of MoSe₂, with superior catalytic activity, and MoO₃, with strong adsorption capacity, not only enhance sulfur utilization but also effectively suppress the shuttling effect. As a result, the MoSe₂@MoO₃/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 MoSe₂@MoO₃/S cathode demonstrated exceptional long-term cycling stability, achieving a capacity retention of 70.7% after 1000 charge/discharge cycles at 1 C.