Assessing the Suitability of a-SiS Nanosheet as an Anode Material for Multivalent Metal-Ion Batteries

The search for suitable two-dimensional (2D) anode materials is crucial to drive the progress of multivalent metal-ion batteries capable of delivering exceptional performance, specifically with very fast charging and discharging rates. In this research, we have unveiled novel insights at the density functional theory level, with the workability of 2D puckered silicon monosulfide (a-SiS) as a probable anode material for multivalent metal-ion batteries using Na, Ca, and Al ions. Exploring the stability aspects of both structural and dynamic levels in the a-SiS nanosheet was estimated through the calculation of cohesive energy and non-imaginary phonon frequencies. The a-SiS nanosheet exhibited negative adsorption energies of -1.45, -0.92, and -2.67 eV for Na, Ca, and Al ions, respectively. Additionally, it was observed that the introduction of mono-, di-, and tri-metal atoms to the surface of the a-SiS nanosheet transformed its semiconducting nature into a metallic phase. Minimal activation energies for the active ion migration of Na (0.066 eV), Ca (0.067 eV), and Al (0.18 eV) on the surface of the a-SiS nanosheet suggest high diffusion and optimal charge/discharge functionality. Furthermore, diminished mean operating voltages of 0.44 V (Na), 0.43 V (Ca), and 0.55 V (Al) were attained and improved the theoretical storage performance of 2046.81 mAh/g (Na), 1643.02 mAh/g (Ca), and 2422.76 mAh/g (Al) for the a-SiS nanosheet. The results of this work suggest that the a-SiS nanosheet has the potential to play a crucial role as a hopeful anode material for the creation of budget-friendly, high-functioning metal-ion batteries using Na, Ca, and Al ions.