A MoO sheet as a promising electrode material: ultrafast Li-diffusion and astonishing Li-storage capacity.

The potential of MoO crystal as an electrode material is reported, and nanostructural MoO systems, including nanoparticles, nanospheres, nanobelts and nanowires, were synthesized and proved to be advanced electrode materials. A two-dimensional (2D) geometric structure represents an extreme of surface-to-volume ratio, and thus is more suitable as an electrode material in general. Stimulated by the recent fabrication of 2D MoO, we adopted an ab initio molecular dynamics simulation and density functional theory calculation to study the stability and electrochemical properties of a MoO sheet. Identified by a phonon dispersion curve and potential energy curve calculations, the MoO sheet proved to be dynamically and thermally stable. After lithiation, similar to most promising 2D structures, we found that a Li atom can strongly adsorb on a MoO sheet, and the lithiated MoO sheet presented excellent metallic properties. Note that, compared with most promising 2D structures, we unexpectedly revealed that the diffusion barrier of the Li atom on the MoO sheet was much lower and the storage capacity of the MoO sheet was much larger. The calculated energy barrier for the diffusion of Li on the MoO sheet was only 75 meV, and, due to multilayer adsorption, the theoretical capacity of the MoO sheet can reach up to 2513 mA h g. Benefiting from general properties, such as strong Li-binding and excellent conductivity, and unique phenomena, such as ultrafast diffusion capacity and astonishing storage capacity, we highlight a new promising electrode material for the Li-ion battery.