SnSe₂ monolayer is a promising Na host material: A DFT study

Na ion batteries (SIBs) have attained tremendous consideration due to their environmental friendliness, natural abundance and low costs. In this study, the electronic and electrochemical characteristics of SnSe₂ monolayer for SIBs are investigated by using first principle calculations. The electronic structure of 2D SnSe₂ exhibit semiconducting character with band gap of 0.85 eV and 1.4 eV by using PBE-GGA and HSE06 schemes, respectively. Our computation revealed that Na adsorbed SnSe₂ system demonstrate metallic characteristics. With rise of Na loading, the electronic conductivity of the host materials upsurges. An average open circuit voltage (OCV) of 0.662 V is perceived with Na storage capacity of 387 mAhg⁻¹. This capacity is greater than the commercial anode materials (i.e. graphite has storage capacity of 372 mAhg⁻¹ and 273 mAhg⁻¹ for LIBs and KIBs, respectively). Furthermore, a significantly low activation energy (104 meV) for Na diffusion on the SnSe₂ monolayer surface is obtained. Hence, these outcomes suggest that SnSe₂ monolayer is a potential applicant for SIBs.