A density functional theory study of twin T-graphene as an anode material for Na-ion-based batteries
Roya Majidi, Ahmad I. Ayesh
Abstract
The potential features of twin T-graphene for anodic applications are studied. The adsorption energy, energy barrier, maximum storage capacity, and electronic properties are calculated by density functional theory. It is found that Na adsorption on twin T-graphene is an exothermic process. The twin T-graphene shows a high calculated specific capacity for Na atoms compared to graphite and other two-dimensional carbon allotropes. A relatively slight diffusion energy barrier guarantees fast charging as well as discharging process in Na-ion batteries based on twin T-graphene. A transition between semiconducting and metallic properties, as a vital condition for ion diffusion on the anode material, is observed during the adsorption process. The charge exchange between the Na atom to the sheet leads to ionic interaction between the adsorbed atom and the host sheet, which is necessary for the reversibility of Na adsorption on the twin T-graphene sheet in the batteries. Our calculations suggest that twin T-graphene is an appropriate anode material for use in Na-ion batteries.