Two-dimensional Si3C: a promising high-capacity anode material for sodium-ion batteries

Sodium-ion batteries (SIBs) have obtained widespread attention because of the non-toxicity and low cost of element sodium. In this paper, we used first-principles methods to investigate the adsorption and diffusion of Na atom on the surface of Si3C. Calculation results show that the adsorption energy and the diffusion barrier for Na on Si3C are 2.33 and 0.26 eV, respectively, suggesting Si3C has good stability and fast charge/discharge capability as for anode in SIBs. More importantly, the Si3C can adsorb 32 Na atoms, which makes the storage capacity up to 1031 mAh/g. These advantages further suggest that Si3C monolayer could become one of the excellent candidates for anodes in SIBs.