硼掺杂单层MoSi_(2)N_(4)锂离子吸附与扩散行为的第一性原理研究  

First-Principles Study of Adsorption and Diffusion Behaviors of Li-Ion on Boron-Doped MoSi_(2)N_(4) Monolayer

作　　者：程悦桓 马新国[1] 黄楚云 廖家俊 段汪洋 CHENG Yue-Huan;MA Xin-Guo;HUANG Chu-Yun;LIAO Jia-Jun;DUAN Wang-Yang(School of Science,Hubei University of Technology,Wuhan 430068,China;Hubei Engineering Technology Research Center of Energy Photoelectric Device and System,Wuhan 430068,China)

机构地区：[1]湖北工业大学理学院,武汉430068 [2]湖北省能源光电器件与系统工程技术研究中心,武汉430068

出　　处：《无机化学学报》2021年第12期2167-2174,共8页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.51472081)资助。

摘　　要：采用平面波超软赝势方法研究了硼掺杂单层MoSi_(2)N_(4)的锂离子吸附与扩散行为。建立了替换位、间隙位、吸附位硼掺杂单层MoSi_(2)N_(4)三类物理模型(共6种构型)。结果表明:硼原子替换表面氮原子的构型最为稳定,该构型下的锂离子吸附能在-1.540~-1.910 eV之间。通过分析电子密度差分图,可知硼掺杂引起MoSi_(2)N_(4)表面的电荷重新分布,即硼与氮获得了来自锂离子的电子转移,导致锂离子在其表面吸附能增加。比较锂离子在硼掺杂MoSi_(2)N_(4)表面的吸附能,推断其扩散路径为D→F,扩散势垒为0.077 eV,表明锂离子在该表面具有较高的脱嵌速率。The adsorption and diffusion behaviors of Li-ion on boron-doped MoSi_(2)N_(4) monolayer were studied by ultrasoft pseudopotential plane-wave method.We established three physical models:substitution sites,interstitial sites and adsorption sites of boron-doped MoSi_(2)N_(4) monolayer,including six doped configurations.The results show that boron substitution for nitrogen on the surface is the most stable,and the adsorption energy of Li-ion on the con-figuration is between-1.540 and-1.910 eV.The charge density difference diagram indicates that both boron and nitrogen on the surface accept part of electrons from the Li-ion,which leads to the enhancement of adsorption ener-gy.According to the potential energy difference of Li-ion adsorption on the surface of boron-doped MoSi_(2)N_(4),it con-cludes that the diffusion pathway is D→F and the corresponding diffusion barrier is 0.077 eV,it is confirmed that the Li-ion has high extraction-insertion rate on the surface of boron-doped MoSi_(2)N_(4) monolayer.

关 键 词：锂离子电池 第一性原理 二维材料 

分 类 号：O649[理学—物理化学] O613.81[理学—化学]