Phase molybdenum disulfide (1T-MoS₂) holds significant promise as an anode material for sodium-ion batteries (SIBs) due to its metallic conductivity and expanded interlayer distance. However, the practical application of 1T-MoS₂ is hindered by its inherent thermodynamic metastability, which poses substantial challenges for the synthesis of high-purity, long-term stable 1T phase MoS2. Herein, a synergetic ethanol molecule intercalation and electron injection engineering is adopted to induce the formation and stabilization of 1T-MoS2 (E-1T MoS2). The obtained E-1T MoS2 consists of regularly arranged sphere-like ultrasmall few-layered 1T-MoS2 nanosheets with expanded interlayer spacing. The high intrinsic conductivity and enlarged interlayer spacing are greatly favorable for rapid Na+ or e- transport. The elaborated nanosheets structure can effectively relieve volume variation during Na+ intercalating/deintercalating processes, shorten transport path of Na+, and enhance diffusion kinetics. Furthermore, a novel sodium reaction mechanism involving the formation of MoS2 nanoclusters during cycling is revealed to produce the higher surface pseudocapacitive contribution to Na+ storage capacity, accelerating Na+ reaction kinetics, as confirmed by the kinetics analysis and ex-situ structural characterizations. Consequently, the E-1T MoS2 electrode exhibits an excellent sodium storage performance. This work provides an important reference for synthesis and reaction mechanism analysis of metastable metal sulfides for advanced SIBs.
Bi et al. (2025) studied this question.