Theoretical prediction of the potential of using two-dimensional V2S2 as an effective anode for alkali metal ion batteries

Abstract

This study investigates proper anode of alkali metal-ion batteries (MIBs) in response of urgent demand for effective devices for storing energy. The 2D V2S2 system can be a potential material as a MIB anode. We have employed the density functional formalism to examine the energetical, dynamic, mechanical, and thermal stability of pristine V2S2 monolayer. The pristine monolayer has inherent metallicity, which satisfies one of the criteria for being an electrode material. The electrical and structural characteristics of the V2S2 systems with the adsorbates of alkali metals and the charge transfer within the system are explored. The barriers of Li, Na, and K migration are computed as 0.42 eV, 0.12 eV, and 0.14 eV, respectively. In addition, our predicted systems demonstrate a significant theoretical capacity of 968.9 mAh/g of the lithium and sodium atoms. The computed open-circuit voltages support that this monolayer can be a practical 2D anode.