The mechanical stability of electrode materials in lithium-ion batteries (LIBs) is critical for their safe usage. Two-dimensional (2D) materials have been widely studied to be used as electrode materials for LIBs. In this paper, the mechanical properties of several typical 2D materials, including graphene, silicene and MoS₂ monolayer upon lithium intercalation were studied, based on the density functional theory calculations with the model developed by Topsakal and Ciraci (Appl Phys Lett 96:091912, 2010). It was found that the in-plane stiffness of 2D materials decreases with increases of lithium concentration. In-plane stiffness decreased about 9.8% at lithium concentration of 0.184 Li/Ų for graphene and 6.0% at a concentration of 0.153 Li/Ų for silicene. The evolution of in-plane stiffness of MoS₂ monolayer as a function of lithium concentration and electron-doping concentration were compared. The in-plane stiffness of MoS₂ monolayer decreased with increases of Li and electron concentration, which revealed that the electron doping effect is the mechanism causing the decrease of the mechanical stability of electrode materials upon lithiation.

锂离子电池（LIB）中电极材料的机械稳定性对于其安全使用至关重要。二维（2D）材料已被广泛研究用作LIB的电极材料。本文基于Topsakal和Ciraci（Appl Phys Lett 96：091912）开发的模型，根据密度泛函理论计算，研究了几种典型的二维材料（包括石墨烯，硅烯和MoS ₂单层在锂嵌入时）的力学性能。2010）。发现2D材料的面内刚度随着锂浓度的增加而降低。面内刚度约9.8％降低在锂浓度的0.184锂/ A ²为石墨烯和6.0％以0.153的Li /埃的浓度²用于硅树脂。比较了MoS ₂单层的面内刚度随锂浓度和电子掺杂浓度的变化。MoS ₂单层的面内刚度随Li和电子浓度的增加而降低，这表明电子掺杂效应是导致锂化时电极材料机械稳定性降低的机理。