Spongy Silicon-Doped MoS2 via Long-Chain Molecule Induction and Mesopore Confinement for Ultra-Stable Lithium-Ion Storage

Abstract

Layered transition metal dichalcogenides (LTMDs), such as MoS₂, are promising anode materials for high-energy-density lithium-ion batteries (LIBs) due to their high specific capacities. However, their practical applications are hindered by poor cycling stability resulting from the instable structure during charge/discharge and inherently low electronic conductivity. To tackle these issues, herein, this study presents the design and synthesis of spongy silicon-doped MoS₂ induced by the long-chain molecules in mesopores. The material consists of few-layered nanofragments with high porosity, resulting in abundant edge sites and sulfur vacancies. These structural features can promote Li⁺ transport and accommodate electrode volume changes during charge/discharge. Electrochemical and theoretical analyses reveal that silicon doping enhances the electronic conductivity of MoS₂, while the nanostructure design enables reversible Li⁺ diffusion along the edges, distinct from Li⁺ storage in the interlayers of conventional MoS₂ anodes. Notably, the material delivers a high reversible capacity of 767.9 mAh g⁻¹ at 0.1 A g⁻¹ and exhibits remarkable rate capability. Moreover, it demonstrates superior cycling stability with over 83% capacity retention even after 1000 cycles at 1.0 A g⁻¹, outperforming most existing MoS₂-based anode materials. This work paves a new way for designing high-performance LTMD-based anodes for LIBs and beyond.