论文标题
二维石墨烯-HFS $ _2 $ van der waals异质结构作为碱性电池的电极材料
Two-Dimensional graphene-HfS$_2$ van der Waals heterostructure as electrode material for Alkali-ion batteries
论文作者
论文摘要
重复充电和放电期间的不良电导率和大量膨胀是当前使用中许多电池电极材料的特征。这导致了2D材料，特别是多层2D系统，被视为替代方案。在这些2D多层系统中，有基于石墨烯的范德华异质结构，具有过渡金属Di-Chalcogenides（TMDC）作为其中一层。因此，在这项研究中，已将二硫化石墨烯二硫化物（GR-HFS $ _2 $）系统研究为用于用作电池电极的原型GR-TMDC系统。密度功能理论的计算表明，GR-HFS $ _2 $ van der waals异质结构形成在能量上受到青睐。为了探测其电池电极应用功能，在异质结构的层之间引入了LI，Na和K intercalants。发现LI和K是良好的插入物，因为它们具有低扩散屏障和正向开路电压。与双层石墨烯和双层HFS $ _2 $的比较表明GR-HFS $ _2 $是一个有利的电池电极系统。
Poor electrical conductivity and large volume expansion during repeated charge and discharge is what has characterized many battery electrode materials in current use. This has led to 2D materials, specifically multi-layered 2D systems, being considered as alternatives. Among these 2D multi-layered systems are the graphene-based van der Waals heterostructures with transition metal di-chalcogenides (TMDCs) as one of the layers. Thus in this study, graphene-Hafnium disulphide (Gr-HfS$_2$) system, has been investigated as a prototype Gr-TMDC system for application as battery electrode. Density functional theory calculations indicate that Gr-HfS$_2$ van der Waals heterostructure formation is energetically favoured. In order to probe its battery electrode applications capability, Li, Na and K intercalants were introduced between the layers of the heterostructure. Li and K were found to be good intercalants as they had low diffusion barriers as well as positive open circuit voltage. A comparison to bilayer graphene and bilayer HfS$_2$ indicate that Gr-HfS$_2$ is a favourable battery electrode system.
