Intercalation-induced electronic reconstruction: Unlocking stable 1T-MoS₂ with expanded interlayers for lithium-ion batteries

Metal-phase molybdenum disulfide (1T-MoS₂), as a layered material, has attracted much attention in recent years due to its excellent electrical conductivity and lithium storage capacity. Although various methods have been applied to optimize the electrochemical properties of MoS₂, how to further enhance its performance by modulating its interlayer structure and electronic properties is still a problem waiting to be solved. In this study, the modulation effects of different metal ions (Mg/Li/Ni) on 1 T-MoS₂ were explored by the metal ion intercalation method, and Mg intercalation was proposed as a new strategy to enhance the electrochemical performance of 1T-MoS₂. Compared with Li and Ni, Mg could more significantly reduces the interlayer expansion of MoS₂, stabilizes its 1T phase, and promotes the rapid diffusion of lithium ions through its unique multi-electron storage effect and strong ion diffusion mechanism. Through a combination of density-functional theory (DFT) calculations and electrochemical tests, it is verified that the Mg intercalation significantly enhances both the ionic conductivity and cycling stability of MoS₂ through the mechanisms of electronic structure modulation and interlayer spacing expansion. The electrochemical results show that the MoS₂ with Mg intercalation reaches a high specific capacity of 2682 mAh g⁻¹ after 400 cycles at 0.5 A g⁻¹, which is superior to that of the MoS₂ with Li (1006 mAh g⁻¹) and Ni (1058 mAh g⁻¹) intercalation. This study provides a new idea for the further design of highly efficient and stable anode materials for Li-ion batteries (LIBs).