锂离子电池二维T-BN/T-graphene异质结阳极材料性能的理论研究  

Theoretical Study on the Performance of Two-dimensional T-BN/T-graphene Heterojunction as Anode for Lithium-ion Batteries

作　　者：高国翔 熊鑫 刘春生[2] 叶小娟 GAO Guoxiang;XIONG Xin;LIU Chunsheng;YE Xiaojuan(College of Integrated Circuit Science and Engineering,Nanjing University of Posts and Telecommunications,Nanjing 210023,China;College of Electronic and Optical Engineering,Nanjing University of Posts and Telecommunications,Nanjing 210023,China)

机构地区：[1]南京邮电大学集成电路科学与工程学院 [2]南京邮电大学电子与光学工程学院,南京210023

出　　处：《高等学校化学学报》2024年第12期95-103,共9页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:61974068)资助.

摘　　要：通过基于密度泛函理论的第一性原理计算,研究了由二维T-BN和T-graphene组成的异质结(T-BN/T-graphene)作为锂离子电池(LIBs)阳极材料的综合性能.计算结果表明,T-BN/T-graphene异质结阳极材料展示了较低的扩散势垒(0.30~0.61 eV)、较大的理论容量(678.5 mA∙h/g)、适当的平均开路电压(1.06 V)和较小的晶格常数变化(0.86%/0.44%).与单层T-BN和单层T-graphene相比,T-BN/T-graphene异质结在扩散性能方面略有改善,最低扩散势垒降至0.30 eV,表明其具有较快的充放电能力.In recent years,with the wide spread application of electronic devices and the popularity of new energy vehicles,lithium-ion batteries(LIBs)attract much of attention due to their high charging/discharging rates and high energy density.Meanwhile,two-dimensional(2D)heterojunctions have shown significant potential in the research of LIBs anode materials due to their high conductivity,low volume expansion,good cycle life and stability,and high specific surface area.Therefore,we investigated the performance of heterojunction composed of 2×2 T-BN and 3×3 T-graphene tilted at 45°as anode materials for LIBs through first-principles calculations based on density functional theory.The band structure of the T-BN/T-graphene heterojunction exhibited metallicity,indicating its good conductivity.The adsorption energy of a single Li ranged from-0.18 eV to-1.48 eV.As an anode material for LIBs,the T-BN/T-graphene heterojunction also exhibited a lower diffusion barrier(0.30—0.61 eV),a larger theoretical capacity(678.5 mA∙h/g),an appropriate average open circuit voltage(1.06 V),and a smaller lattice constant change(0.86%/0.44%).Compared with T-BN and T-graphene monolayer,the T-BN/T-graphene heterojunc⁃tion has slightly improved diffusion behavior of Li,with the lowest diffusion barrier of 0.3 eV,indicating its fast charging/discharging ability.Overall,the T-BN/T-graphene heterojunction is expected to become an effective design approach for high-quality anode materials in LIBs.

关 键 词：第一性原理计算 二维材料 异质结 锂离子电池 

分 类 号：O641[理学—物理化学] O646[理学—化学]