First-principles investigations of vanadium disulfide for lithium and sodium ion battery applications

摘要

Recently, two-dimensional (2D) layered transition metal dichalcogenides (LTMDs) have attracted great scientific interest for ion battery applications. Because of its remarkable metallic property, vanadium disulfide (VS2) as a typical family member of LTMDs, can be an alternative anode material for ion battery applications. In this paper, we systematically investigate the adsorption energy and diffusion coefficient of the lithium and sodium ions in monolayer and bulk VS2 for lithium and sodium ion batteries by a density functional theory method. Our calculations show that the VS2 capacity can reach up to 466 mA h g(-1). It exhibits a low output voltage of 0.72 and 0.48 V for lithium and sodium ion batteries in the monolayer VS2 as well as an output voltage of 0.88 and 0.6 V in the bulk VS2, respectively. The calculated lithium and sodium ion diffusion coefficients in the bulk VS2 are enhanced by five and seven orders of magnitude compared to the reported bulk MoS2, respectively. Our investigations also reveal that VS2 exhibits better electrochemical performance as an anode in the sodium ion battery than in the lithium ion battery.