CrSi_(2)P_(4)和CrSiGeP_(4)单层作为锂离子电池阳极材料的第一性原理研究

First-principles study of CrSi_2P_(4) and CrSiGeP_(4) monolayers as anode materials for Li-ion batteries

设计优良的电极材料是提高锂离子电池性能的关键.二维材料作为金属离子电池的电极,具有存容量高、电子/离子电导性能优异的特征,在储能领域显示出广阔的应用前景.采用第一性原理计算,探索二维CrSi_(2)P_(4)和CrSiGeP_(4)单层作为锂离子电池电极材料的可行性,并阐明这种结构在提高电池性能方面的优势.基于此,建立了CrSi_(2)P_(4)和CrSiGeP_(4)单层模型,并对其电子特征进行了分析.结果表明,二维Cr Si_(2)P_(4)单层是窄带隙半导体材料,且具有良好的稳定性和较高的离子电导能力(锂离子扩散能垒为0.17 eV);二维CrSiGeP_(4)单层的带隙比Cr Si_(2)P_(4)单层小(0.14 eV),其结构稳定性和离子电导能力(0.72 eV)都低于CrSi_(2)P_(4)单层.因此,CrSi_(2)P_(4)单层有望成为一种极具吸引力的锂离子电池电极材料,为新材料在电池领域的应用提供了前期理论探索.

Designing excellent electrode materials is the key challenge to improve the performance of lithium-ion batteries(LIBs).As the electrodes of metal ion batteries,two-dimensional material has the characteristics of high storage capacity and excellent electron/ion conductance,which shows broad application prospect in the field of energy storage.Use first-principles calculations to explore the possibility of two-dimensional CrSi_2P_(4) and CrSiGeP_(4monolayers) as electrode materials for lithium-ion batteries,and illustrate the advantages of this structures in improving battery performance.On this basis,have established models of CrSi_2P_(4) and CrSiGeP_(4) monolayers and analyzed their electronic characteristics.The results show that the 2D CrSi_2P_(4) monolayer is a narrow band gap semiconductor material with good stability and high ion conductivity(lithium ion diffusion energy barrier is 0.17eV).The 2D CrSiGeP_(4) monolayer has a smaller band gap(0.14 eV)than the CrSi_2P_(4) monolayer,and its structural stability and ionic conductivity(0.72 eV)are poorer than that of the CrSi_2P_(4) monolayer.Therefore,CrSi_2P_(4is) expected to become a very attractive electrode material for lithium-ion batteries,providing a preliminary theoretical exploration for the application of new materials in the battery field.