First principles study on monolayer GeTe as an anode material for multivalent ion batteries

Finding suitable anode materials for multivalent ion batteries (MuIBs) is the key to improving theoretical capacity, reducing development costs and enhancing the safety of energy storage batteries. In recent years, monolayer GeTe has been reported as an anode material in monovalent ion batteries, but it has not received much attention in MuIBs. This article uses first principles methods based on density functional theory (DFT) to explore the application prospects of monolayer GeTe with a unique serrated wrinkled layer structure as an anode material for multivalent metal ion (Al³⁺/Mg²⁺/Ca²⁺) batteries. The research results show that Al³⁺, Mg²⁺ and Ca²⁺ have low diffusion barriers (0.47, 0.35 and 0.61 eV) on monolayer GeTe, indicating its excellent diffusion ability and fast charge discharge rate during the charging and discharging process. Reasonable open circuit voltages (0.62, 0.85 and 0.64 V) and theoretical specific capacities higher than those of commercial graphite anode materials (624.6, 446.1 and 446.1 mA h g^-1) indicate that monolayer GeTe has the ability to store Al³⁺/Mg²⁺/Ca²⁺. Finally, molecular dynamics simulations (MD) are used to calculate the adsorption energy and density field of ions during their movement on the surface of monolayer GeTe, demonstrating the stable adsorption ability of monolayer GeTe and the strong interaction between the two. This article reveals that monolayer GeTe can be used as a promising candidate anode material for MuIBs.