Research on the bonding and sodium storage properties of the Sn-C interface

Abstract

In this paper, with the method of a first-principle plane wave, the bonding and sodium storage properties of the Sn-C Interface were studied as anode materials for sodium-ion batteries. The results show that the formation energy of sodium intercalation in Sn-C-1 is 2.4622 eV, lower than the 2.8912 eV of Sn-C-2. The volume expansion ratio of Sn-C-1 after sodium insertion is negative, with a theoretical specific capacity of 441.9223 mAh g -1 . The volume expansion ratio of Sn-C-2 is up to 543.2273%. The conductivity of Sn-C-2 is stronger than that of Sn-C-1. The sodium ion is easy to be redissociated in the sodium removal reaction. The reversibility of sodium ion insertion into Sn-C-2 is not as good as that of Sn-C-1. Sn-C-1 is superior to Sn-C-2 as an anode material for sodium ions based on the consideration of important parameters, such as reversible insertion and removal of sodium ions, volume expansion ratio, etc.