二维VC_(2)作为钠离子电池负极材料的理论研究  

Theoretical study of two-dimensional VC_(2) as an anode material for sodium-ion batteries

作　　者：潘美玲 孙楠楠 赵志超 PAN Meiing;SUN Nannan;ZHAO Zhichao(Hebei University of Water Resources and Electric Engineering,Cangzhou 061000,Hebei,China)

机构地区：[1]河北水利电力学院,河北沧州061000

出　　处：《储能科学与技术》2025年第2期497-504,共8页Energy Storage Science and Technology

基　　金：河北水利电力学院基本科研业务费专项资金资助(SYKY2221),河北省自然科学基金(B2021412001)。

摘　　要：钠离子电池的发展离不开高性能负极材料的合理设计,具有C_(2)二聚体的二维过渡金属碳化物因其高碳原子质量暴露在表面,表现出比其他二维过渡金属碳化物更加优异的电极材料性能。本工作选择具有较高结构稳定性的C_(2)二聚体VC_(2)单分子层为目标材料,利用第一性原理对其结构电子性质和钠离子在该结构表面的存储性能进行研究。存储性能的计算包括钠离子在VC_(2)表面的吸附位点、多层吸附行为、扩散路径以及开路电压等关键参数。结果表明,VC_(2)单分子层结构稳定性高、导电性良好,具备优异的钠离子存储性能,基于多层钠离子吸附,其对Na的理论容量为715 mAh/g,扩散能垒是0.23 eV,保证了较快的充放电速率。随着钠离子浓度的增加,平均总吸附能始终为负。此外,开路电压的计算表明,Na插层电压的变化是稳定的,以上结果均表明VC_(2)单分子层有望成为钠离子电池的理想负极材料。本研究有助于为寻找高性能钠离子电池负极材料提供新的思路,为进一步优化和设计此类材料提供理论依据。The rational design of high-performance anode materials is crucial for advancing sodium-ion battery technology.Among potential candidates,two-dimensional transition metal carbides,particularly those incorporating C_(2) dimer structures,exhibit superior electrode material properties owing tothe high carbon atomic mass on their surfaces.Consequently,we selected the VC_(2) monolayer,featuring a highly stable a C_(2) dimer structure,for investigation.Utilizing first-principles calculations,we evaluated its structural and electronic properties,as well as its sodium-ion storage performance on the surface,includingadsorption sites,multilayer adsorption dynamics,diffusion pathways,and open-circuit voltage.Our findings reveal that the VC_(2)monolayer exhibits exceptional structural stability and electrical conductivity,strongly suggesting its suitability for sodium-ion storage applications.Theoretical calculations predict a substantial sodium-ion adsorption capacity for multi-layer VC_(2),reaching 715 mAh/g.Furthermore,the calculated low-diffusion energy barrier of 0.23 eV ensures swift charging and discharging rates.Notably,as the sodium-ion concentration escalates,the average total adsorption energy remains consistently negative.Furthermore,open-circuit voltage calculations underscore the stability of sodium intercalation voltage.Collectively,these results underscore the potential of VC_(2) monolayers as an ideal anode material for sodium-ion batteries.This study not only introduces a novel perspective for the pursuit of high-performance anode materials but also lays a theoretical foundation for the subsequent optimization and design of such materials.

关 键 词：钠离子电池 第一性原理 二维材料 

分 类 号：O646[理学—物理化学]