Li–S Chemistry of Manganese Phosphides Nanoparticles With Optimized Phase

The targeted synthesis of manganese phosphides with target phase remains a huge challenge because of their various stoichiometries and phase-dependent physicochemical properties. In this study, phosphorus-rich MnP, manganese-rich Mn2 P, and their heterostructure MnP-Mn2 P nanoparticles evenly dispersed on porous carbon are accurately synthesized by a convenient one-pot heat treatment of phosphate resin combined with Mn2+ . Moreover, their electrochemical properties are systematically investigated as sulfur hosts in lithium-sulfur batteries. Density functional theory calculations demonstrate the superior adsorption, catalysis capabilities, and electrical conductivity of MnP-Mn2 P/C, compared with MnP/C and Mn2 P/C. The MnP-Mn2 P/C@S exhibits an excellent capacity of 763.3 mAh g-1 at 5 C with a capacity decay rate of only 0.013% after 2000 cycles. A phase evolution product (MnS) of MnP-Mn2 P/C@S is detected during the catalysis of MnP-Mn2 P/C with polysulfides redox through in situ X-ray diffraction and Raman spectroscopy. At a sulfur loading of up to 8 mg cm-2 , the MnP-Mn2 P/C@S achieves an area capacity of 6.4 mAh cm-2 at 0.2 C. A pouch cell with the MnP-Mn2 P/C@S cathode exhibits an initial energy density of 360 Wh kg-1 .