Cyclically Generated Phase Segregation Synergizing with Si Enhances Lithium-Ion Storage Capability

Abstract

Silicon-based materials has been focused as potential candidates for lithium-ion battery anodes due to their sufficient reserves and extremely high specific capacity. However, the drastic volume expansion during the cycling leads to material pulverization and instability of the solid-electrolyte interface resulting in the rapid capacity fading, which restricts their commercial application. In this study, an original synergistic effect resulting from the phase segregation of Mn-based metal organic framework (Mn-MOF) during cycling is proposed to modify silicon via a facile self-assembly method and investigated as an anode material in LIBs. The unique composite structure can effectively improve the reversibility of silicon and enhance the lithium-ion storage capability. After 400 cycles, the Si@Mn-MOF composite exhibits a good electrochemical performance, achieving a high reversible capacity retention of 1234.4 mAh g⁻¹ at a current density of 200 mA g⁻¹.