SiS2 monolayer: An auspicious alkali-ion anode material with high specific capacity and ultrafast ion diffusion

Over the past few years, two-dimensional materials using as electrode of metal-ion batteries have attracted extensive attentions due to its excellent performance. Very recently, a novel monolayer (ML) SiS2 with hexa-coordinated atomic conformation has been proposed. In this work, the capability of ML SiS2 used as anode for Li, Na, and K-ions batteries has been comprehensive appraised via first-principles calculations. Our finding shown that the whole adsorption system is stable, and after adsorbing Li, Na and K atoms, the ML SiS2 changes from semiconductivity to metallicity. In particular, Li, Na, and K-ions prefer disperse along the path I in ML SiS2 and the corresponding migration barrier height are 0.210, 0.130 and 0.076 eV, respectively. Consequently, ML SiS2 exhibits high rate performance. Besides, the maximum storage capacity of ML SiS2 used as Li, Na, and K-ion batteries anode material are 581.280, 435.960 and 435.960 mAh/g, and the nominal open-circuit voltages for Li, Na, and K-ion batteries are 0.460, 0.380 and 0.620 V, respectively. These prominent properties indicate that ML SiS2 is an auspicious metal-ion anode material.