Figure 4. Strain-induced modulation of chemical conversion in vertically stacked C-MoS₂ nanosheets.

(a) Scheme showing the different chemical states between interface-strained MoS₂ nanosheets and pristine MoS₂ nanosheets after Li insertion, showing chemical conversion for stacked C-MoS₂ and intercalation for pristine MoS₂. Ex situ Raman spectroscopy confirming the electrochemical signature of chemical conversion based on the Raman mode of polysulfides at 746 cm⁻¹ is presented for both materials at (b). Open-circuit voltage (OCV), (c) 1.75 V and (d) 0.01 V versus Li/Li⁺. Notably, at 1.75 V versus Li/Li⁺, the vertically stacked C-MoS₂ nanosheets have undergone chemical conversion, whereas the pristine MoS₂ nanosheets remain unconverted.