First-principles investigation of N-triphenylene-graphdiyne nanosheets as an anode material for Na, K, Mg and Ca storage

Advances in rechargeable metal-ion battery technologies depend on the design of novel electrode materials to enhance the storage capacity and charging/discharging rates. Two dimensional (2D) materials have recently gained remarkable interest for various applications and in particular for energy storage systems. Graphdiyne nanosheets have been fabricated recently and show great storage capacities for Li-ion batteries. In this study, we investigate the performance of the novel graphdiyne material, nitrogenated-triphenylene graphdiyne (N-TpG) monolayer as an anode material for Na-, K-, Mg-, and Ca-ion storage using density functional theory simulations. Our first-principles simulations results indicate that N-TpG nanosheets can yield ultrahigh capacities of 1439 mAh g(-1), 1871 mAh g(-1), 2159 mAh g(-1) and 4319 mAh g(-1), for Mg-, K-, Na-, and Ca-ions storage, respectively. The obtained results confirm the metallic electronic behaviour of the N-TpG nanosheets with metalions adsorbed over the surface. In summary, our results suggest N-TpG nanosheets as a highly promising candidate for the design of advanced energy storage devices with ultrahigh charge capacities.