Engineering bimetal phosphorus trisulfides heterointerface in semi-open frame structure for lithium-sulfur batteries

Monofunctional host materials of lithium-sulfur (Li-S) batteries are inadequate to simultaneously address the complex issues including “shuttle effect” and sluggish redox kinetics. Herein, iron and manganese bimetallic phosphorus trisulfide (Fe-MnP 2 S 6 ) with heterointerfaces and a semi-open frame structure was synthesized as a multifunctional host material for Li-S batteries. Theoretical calculations suggest that due to the strong electronic coupling effect, electrons migrate from the MnPS 3 layer to the FePS 3 layer, accelerating charge and ion transfer on the surface of FePS 3 . The d-band center of metal atoms shifts towards the Fermi level through the introduction of Mn 2 P 2 S 6 , enhancing the interaction with polysulfides . Moreover, the frame exhibits excellent structural stability and physical limiting ability of sulfur. As a result, the cell with Fe-MnP 2 S 6 delivers impressive electrochemical performance and redox kinetics, including a capacity of 1388 mAh/g at 0.2C, a rate performance of 850 mAh/g at 4C and a capacity attenuation rate of 0.028 % per cycle over 1,000 cycles at 1C. Through meticulous structural design and optimal composition adjustments, our work explores the mechanism of metal phosphorus trisulfides (MPS 3 ) in Li-S batteries.