Monolayer Molybdenum Disulfide (MoS2) is a promising anode material for lithium ion batteries because of its high capacities. In this work, first principle calculations based on spin density functional theory were performed to investigate adsorption and diffusion of lithium on monolayer MoS2 with defects, such as single- and few-atom vacancies, antisite, and grain boundary. The values of adsorption energies on the monolayer MoS2 with the defects were increased compared to those on the pristine MoS2. The presence of defects causes that the Li is strongly bound to the monolayer MoS2 with adsorption energies in the range between 2.81 and 3.80 eV. The donation of Li 2s electron to the defects causes an enhancement of adsorption of Li on the monolayer MoS2. At the same time, the presence of defects does not apparently affect the diffusion of Li, and the energy barriers are in the range of 0.25–0.42 eV. The presence of the defects can enhance the energy storage capacity, suggesting that the monolayer MoS2 with defects is a suitable anode material for the Li-ion batteries.
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机译:单层二硫化钼(MoS2)由于其高容量而成为锂离子电池的有希望的负极材料。在这项工作中,进行了基于自旋密度泛函理论的第一性原理计算,以研究锂在单层MoS2上的吸附和扩散,该单层MoS2具有缺陷,例如单原子和少原子的空位,反位和晶界。与原始MoS2相比,具有缺陷的单层MoS2上的吸附能值增加了。缺陷的存在导致Li以2.81至3.80 eV的吸附能牢固地结合到单层MoS2上。 Li 2s电子对缺陷的贡献导致Li在单层MoS2上的吸附增强。同时,缺陷的存在显然不会影响Li的扩散,并且能垒在0.25–0.42 eV的范围内。缺陷的存在可以增强能量存储能力,这表明具有缺陷的单层MoS2是适合锂离子电池的阳极材料。
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