Pressure‐Assisted Synthesis of Highly Crystalline 1T′′‐LixMoS2.

LixMoS2 is not only a lithium battery material, but is also an important precursor for the synthesis of MoS2 nanomaterials. Current syntheses of MoS2, such as in n‐butyllithium/LiBH4 or electrochemically, are not satisfying in terms of defined stoichiometry and crystallinity, so an accurate experimental crystal structure determination of this important and widely used material has been long awaited. A high‐pressure/high‐temperature synthesis yielded highly crystalline 1T′′‐LixMoS2 (x=1, 1.333). 1T′′‐LiMoS2 crystallizes in the space group P1‾ $\bar 1$ with a=6.2482(3) Å, b=6.6336(3) Å, c=6.7480(3) Å, α=119.321(2)°, β=90.010(2)° and γ=90.077(2)°. The arrangement of Mo atoms within the b‐c‐plane confirmed a predicted Peierls distortion. A similar atom distribution pattern to that of Mo is also observed for the lithium atoms. Calculation of bond valence site energies gave an activation barrier of 1.244 eV for 2D lithium‐ion migration. For x=1.333, a phase‐pure synthesis was achieved. [ABSTRACT FROM AUTHOR]