In situ electron microscopic observation of electrochemical Li-intercalation into MoS2

In this work, lithium (Li) intercalation into molybdenum disulfide (MoS2) is observed by in situ transmission electron microscope (TEM). A solid-state electrochemical reaction is carried out in a vacuum of TEM column using an electrochemical probe holder. The Li-intercalation proceeds radially from a connecting point between Li2O and MoS2. The 2H-1 T structural transition of the MoS2 layer accompanied by the lithiation is identified by electron diffractions. The electron energy loss spectra (EELS) of the lithiated and non-lithiated areas indicated that the electronic properties of the MoS2 layer changed after the lithiation.