Mo3P/Mo heterojunction for efficient conversion of lithium polysulfides in high-performance lithium-sulfur batteries

Realizing efficient immobilization of lithium polysulfides (LiPSs) as well as reversible catalytic conversion between LiPSs and the insoluble Li₂S is vital to restrain the shuttle effect, which requires highly reactive catalysts for high-performance Li-S batteries. Here, three-dimensional ordered porous Mo-based metal phosphides (3DOP Mo₃P/Mo) with heterogeneous structures were fabricated and utilized as separator-modified coatings for Li-S batteries to catalyze the conversion of LiPSs. The adsorption, catalytic and electrochemical performance of the corresponding cells were compared among 3DOP Mo₃P/Mo and 3DOP Mo, by kinetic and electrochemical performance measurements. It was found that the cell with 3DOP Mo₃P/Mo modified separator deliver better electrochemical performance, with a high specific capacity of 469.66 mAh g^-1 after 500 cycles at a high current density of 1°C. This work provides an idea and a guideline for the design of the separator modification for high-performance Li-S batteries.