摘要
使用第一性原理方法系统地计算研究层状SnSe_2材料中锂离子吸附和迁移。发现锂原子在SnSe_2表面被强烈吸附,结合能(> 3 eV)显著大于石墨烯、磷烯、MoS2等二维层状材料。Bader电荷分析表明锂原子的几乎整个2s电子电荷都转移给了SnSe_2,锂原子以正离子的形式存在。单层SnSe_2表面锂离子的迁移势垒为0. 197 eV,低于石墨烯、MoS2等二维层状材料。基于单层SnSe_2的锂离子电池理论,平均开路电压为3. 05 V。此外,锂离子的插入也带来了从半导体态向金属态的转变,从而具有较好的电导率。这些发现增进了对层状过渡金属二硫化物材料中锂离子吸附性质和迁移机制的理解。
The properties of Li-ion adsorption and migration in layered SnSe2 are systematically investigated using the first principle calculations.It is found that the Li atoms are adsorbed strongly on substrate SnSe2,and the binding energy（ 〉 3 eV） is significantly higher than those on graphene,phosphorene,MoS2,and some other two-dimensional（ 2D） layered materials.Bader charge analysis reveals that almost the whole charge of 2 s electron of the Li atom transfers to substrate SnSe2 and Li exists in the cationic state.The Li-ion migration energy barrier for monolayer SnSe2 is 0.197 e V,which is significantly lower than those for graphene,MoS2,and other 2D materials.The average open-circuit voltage of 3.05 V is predicted in the monolayer SnSe2-based Li-ion battery.The Li intercalation also leads to a transition from semiconductor to metallic state and gives rise to a good electrical conductivity.These findings provide insights into the Li-ion adsorption properties and migration mechanism in layered transition-metal dichalcogenide.
作者
方林灿
郝宽荣
闫清波
郑庆荣
FANG Lincan;HAO Kuanrong;YAN Qingbo;ZHENG Qingrong(College of Materials Science and Opto-Electronic Technology,University of Chinese Academy of Sciences,Beijing 100049,China;School of Physics,University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《中国科学院大学学报（中英文）》
CSCD
北大核心
2018年第6期735-742,共8页
Journal of University of Chinese Academy of Sciences
基金
Supported by National Basic Research Program(2012CB932900)
