Design of tetracene-based metallic 2D carbon materials for Na- and K-Ion batteries

Inspired by the tunable electronic properties and high charge carrier mobility of recently synthesized tetracene-based nanoribbons (TNRs) [Chem. Eur. J. 2019, 25, 12074], for the first time we design two dimensional (2D) metallic carbon materials by using tetracene (T) as a basic building block. Based on first-principles calculations, we show that the resulting metallic 2D carbon allotropes namely C18 and C36H8 are dynamically and thermally stable. Moreover, the porous C18/C36H8 sheets have multiple adsorption sites with strong binding energies for Na/K ions and exhibit a high storage capacity of 991.82/1277.93 mAh/g, low voltage of 0.12/0.46 V and low energy barriers 0.46/0.029 eV respectively. These remarkable findings suggest the applicability of metallic carbon allotropes C18 and C36H8 as promising anode materials for Na- and K-ion batteries.