  We present measurements of weak localization on hexagonal boron nitride
encapsulated bilayer MoS$_2$. From the analysis we obtain information regarding
the phase-coherence and the spin diffusion of the electrons. We find that the
encapsulation with boron nitride provides higher mobilities in the samples, and
the phase-coherence shows improvement, while the spin relaxation does not
exhibit any significant enhancement compared to non-encapsulated MoS$_2$. The
spin relaxation time is in the order of a few picoseconds, indicating a fast
intravalley spin-flip rate. Lastly, the spin-flip rate is found to be
independent from electron density in the current range, which can be explained
through counteracting spin-flip scattering processes based on electron-electron
Coulomb scattering and extrinsic Bychkov-Rashba spin-orbit coupling.
