  Valley-spin coupling in transition-metal dichalcogenides (TMDs) can result in
unusual spin transport behaviors under an external magnetic field. Nonlocal
resistance measured from 2D materials such as TMDs via electrical Hanle
experiments are predicted to exhibit nontrivial features, compared with results
from conventional materials due to the presence of intervalley scattering as
well as a strong internal spin-orbit field. Here, for the first time, we report
the all-electrical injection and non-local detection of spin polarized carriers
in trilayer MoS_2 films. We calculate the Hanle curves theoretically when the
separation between spin injector and detector is much larger than spin
diffusion length, \lamda_s. The experimentally observed curve matches the
theoretically-predicted Hanle shape under the regime of slow intervalley
scattering. The estimated spin life-time was found to be around 110 ps at 30 K.
