Germanene nanosheets as a novel anode material for sodium-ion batteries-a first-principles investigation

We report the electronic properties and energetics of bare and hydrogenated germanene nanosheet using density functional theory. Since there is a need for an alternate to Li-ion batteries, the Na-ion batteries (NIB) which are cost effective and long lasting are considered as an alternate to Li-ion batteries. In order to find the suitable anode materials for Na-ion batteries, the present work focus on the surface assimilation of Na/Na+ on the bare germanene and hydrogenated germanene nanosheet and their resulting impacts. The response yielded by the bare and hydrogenated germanene nanosheets on the surface assimilation of Na/Na+ are investigated through the density of states (DOS) spectrum, adsorption energy, charge transfer, and band gap energy. Also, the adsorption of Na and Na+ ions on germanene nanosheets are explored using electron density. The tendency of Na+ to get strongly adsorbed on bare and hydrogenated germanene nanosheets suggest that germanene nanosheets can be used as anode material for NIBs.