  We fabricate ion-gated field-effect transistors (iFET) on mechanically
exfoliated multilayer MoS$_2$. We encapsulate the flake by Al$_2$O$_3$, leaving
the device channel exposed at the edges only. A stable Li$^+$ intercalation in
the MoS$_2$ lattice is induced by gating the samples with a Li-based polymeric
electrolyte above $\sim$ 330 K and the doping state is fixed by quenching the
device to $\sim$ 300 K. This intercalation process induces the emergence of
anomalies in the temperature dependence of the sheet resistance and its first
derivative, which are typically associated with structural/electronic/magnetic
phase transitions. We suggest that these anomalies in the resistivity of
MoS$_2$ can be naturally interpreted as the signature of a transition to a
charge-density-wave phase induced by lithiation, in accordance with recent
theoretical calculations.
