Theoretical study of 2D Janus MoSSe as anode materials for Na-ion batteries with minimal secondary issues

Abstract In this study, the capability of bilayer and monolayer MoSSe (Molybdenum sulfide selenide) as an anode material for Na-ion batteries is performed using the first-principles DFT calculations. The electronic stability is confirmed by negative formation energy (−0.077 eV) of the bilayer and (−5.96 eV) monolayer MoSSe. The parameters of battery design are addressed by the adsorption of Na-ions on the bilayer and monolayer MoSSe in different concentrations. The negative adsorption energy is reported for both bilayer and monolayer MoSSe for Na-ions. The increase in adsorption above a certain concentration causes secondary issues (dendrite formation) in Na-ion batteries and is addressed in depth. Additionally, different approaches are shown to reduce the dendrite formation. Further, the charge/discharge kinetics of the bilayer and monolayer MoSSe are studied and evaluated in comparison to commercial batteries. Diffusion-dependent electrical conductivity of 0.01 eV (7.76 × 10 −5 cm 2 sec −1 ) for bilayer and monolayer MoSSe highlights the novelty of our work. Additionally, the recovery time (in the order of picoseconds), energy density and storage capacity for bilayer and monolayer MoSSe suggest their suitability for real-time applications. The adsorbed concentration of a maximum of four and nine Na-ions for bilayer and monolayer MoSSe show cyclic stability with almost zero volume expansion.