In order to clarify the reaction mechanism of the hydrogenation process in the Li2NH system, we have observed the partially hydrogenated samples by transmission electron microscopy (TEM). From the TEM images of partially hydrogenated samples, it was shown that the LiNH2 phase was located between Li2NH phase, which was almost at the center of the particle, and LiH particles with the size of 100 nm. This result indicated that LiH was generated and grew up at the outside of the complex particle of Li2NH and LiNH2 with Li moving from the center to the surface of the particle.
