First principles predictions of Na and K storage in layered SnSe2

The structural model of 1T-SnSe2 is investigated as Na/K host material for SIBs and PIBs. The suitable voltage curves and high Na/K storage capacity provide excellent efficiency of the proposed structure. Additionally, the low activation barriers for Na (104 meV) and K (113 meV) induce monolayer SnSe2 as a potential anode with rapid charging and discharging processes. [Display omitted] •Layered SnSe2 is investigated as Na and K host for SIBs and PIBs employing DFT.•Pristine SnSe2 becomes to be conducting with low content of Na/K loading.•Fast charging and discharging is checked due to low Na and K activation barriers.•The calculated average OCV for Na and K are 0.68 V and 0.48 V with a suitable capacity of 387 mAhg−1. Recent years have witnessed a flow of research in two-dimensional (2D) materials for the development of new rechargeable metal-ion battery systems due to their large surface areas and plenty accommodating sites for the adsorption of metal ions. Inspired from the experimental synthesis of 2D SnSe2 for Na ion batteries, we speculate the adsorption and diffusion mechanism of Na and K on SnSe2 by means of computational approach. Our results disclose strong adsorption strength with Na and K loading, confirming the favorable electrochemical reactions between adsorbates (Na/K) and the host SnSe2. The electronic structure of the host material is displaying the conductive behavior with Na and K loading. Additionally, the low average voltages for Na (0.68 V) and K (0.48 V), and the high theoretical capacity (387.5 mAhg−1) captivate SnSe2 monolayer for Na- and K- ion batteries. Finally, the activation barriers and the energy pathways for Na and K are calculated. The simulated activation barriers for Na and K are as low as 0.104 eV and 0.113 eV, respectively. The current study endows that Na and K storage for SnSe2 sheet could be industrious and productive for the commercialization of Na- and K- ion batteries.