Theoretical study of δ-5 boron monolayer as an anode material for Li- and non-Li-ion batteries

We have studied the electrochemical performance of the δ-5 boron monolayer as an anode material for alkali metal (AM) and alkaline earth metal (AEM) ion batteries using density-functional theory simulations. The electronic properties, adsorption, diffusion rate, and storage behavior of various metal atoms (M) in the δ-5 boron monolayer are explored. Our study shows that the δ-5 boron monolayer possesses high electrical conductivity and a low activation barrier for electron and metal-ion transit (0.493–1.117 eV), indicating a fast charge/discharge rate. Furthermore, the theoretical capacities of the δ-5 boron monolayer for Li, Na, and K are found to be greater than those of commercial graphite. The average open-circuit voltage for AM and AEM is reasonably low and in the range of 0.34–1.30 V. Our results show that δ-5 boron monolayer could be a promising anode material in lithium-ion and non-lithium-ion rechargeable batteries. Graphical abstract