Intercalation and defect engineering of layered MnPS3 for greatly enhanced capacity and stability in sodium-ion batteries

Abstract

Two-dimensional ternary metal phosphorus trisulfides have emerged as promising anode materials for sodium-ion batteries owing to their intriguing layered structure, flexible composition and high surface activity. However, these materials still suffer from low rate capability and poor cycling performance due to pulverization during the de/sodiation processes. Herein, two-dimensional intercalated Mn1−xPS3(Me4N+)2x with vacancy defects and expanded interlamellar spacing is prepared through a mild liquid-phase reaction using MnPS3 powder grown by chemical vapor deposition as the precursor. The vacancy defect regulates the electronic structure and improves the electrical conductivity, while the expanded interlayer space accelerates ion diffusion, providing spacious storage space for Na+ ions and alleviating volume expansion. These synergistic effects collectively enhance the capacity and stability of MnPS3. The prepared Mn1−xPS3(Me4N+)2x electrode affords high capacities of 890 mAh/g at 0.1 A/g and 615 mAh/g at 5 A/g, along with an ultralong cycle life of 700 cycles at 1 A/g with a capacity retention of 94 %. These results hold significant implications in advancing the electrochemical performance of MPS3-based sodium-ion batteries by employing intercalation and defect engineering strategies.