School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China.
Nanotechnology. 2017 Mar 10;28(10):105402. doi: 10.1088/1361-6528/aa56d0. Epub 2017 Jan 5.
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.
钼酸晶体作为电极材料的潜力已被报道，包括纳米颗粒、纳米球、纳米带和纳米线在内的纳米结构 MoO 体系已被合成，并被证明是先进的电极材料。二维（2D）几何结构代表了表面积与体积比的极限，因此通常更适合作为电极材料。受最近制备二维 MoO 的启发，我们采用了从头算分子动力学模拟和密度泛函理论计算来研究 MoO 薄片的稳定性和电化学性能。通过声子色散曲线和势能曲线计算，证明了 MoO 薄片在动力学和热力学上是稳定的。经过锂化后，与大多数有前途的二维结构类似，我们发现一个 Li 原子可以强烈吸附在 MoO 薄片上，而锂化的 MoO 薄片呈现出优异的金属性质。值得注意的是，与大多数有前途的二维结构相比，我们意外地发现 Li 原子在 MoO 薄片上的扩散势垒要低得多，并且 MoO 薄片的存储容量要大得多。Li 在 MoO 薄片上扩散的计算能垒仅为 75 meV，而且由于多层吸附，MoO 薄片的理论容量可达 2513 mA h g。得益于强 Li 结合和优异导电性等一般性质，以及超快扩散能力和惊人存储容量等独特现象，我们为锂离子电池突出了一种新的有前途的电极材料。
