In Situ Electrochemical Activation Derived Li_x MoO_y Nanorods as the Multifunctional Interlayer for Fast Kinetics Li-S batteries

Li-S batteries (LSBs) have attracted worldwide attention owing to their characteristics of high theoretical energy density and low cost. However, the commercial promotion of LSBs is hindered by the irreversible capacity decay and short cycling life caused by the shuttle effect of lithium-polysulfides (LiPSs). Herein, a hybrid interlayer consisting of MoO₃ , conductive Ni foam, and Super P is prepared to prevent the shuttle effect and catalyze the LiPSs conversion. MoO₃ with a reversible lithiation/delithiation behavior between Li_0.042 MoO₃ and Li₂ MoO₄ within 1.7-2.8 V versus Li/Li⁺ combines the Li⁺ insertion and LiPSs immobilization and efficiently improve the LSBs redox kinetics. Benefiting from the reversible Li⁺ insertion/extraction in lithium molybdate (Li_x MoO_y ) and the highly conductive Ni foam substrate, the sulfur cathode coupled with such electrochemical activation derived catalytic interlayer exhibits a high initial discharge capacity of 1100.1 mAh g^-1 at a current density of 1 C with a low decay rate of 0.09% cycle^-1 . Good capacity retention can still be obtained even the areal sulfur loading is increased to 13.28 mg cm^-2 .