Unveiling the electrochemical properties of Au2B/Au2BO2 MBenes for Li- and Na-ion batteries through DFT simulations

The demand for high-performance energy storage solutions has positioned alkali metal-ion batteries as a leading technology for the future. Central to their advancement is the exploration of innovative electrode materials, such as two-dimensional structures with their unique properties that significantly contribute to improving efficiency and capabilities and marking a pivotal step forward in the evolution of next-generation energy storage systems. In this context, stability of atomic arrangements of Au 2 B and oxygenated Au 2 B (Au 2 BO 2 ) were comprehensively evaluated as anode materials for Li- and Na-ion batteries, using first-principles calculations. We explored different termination groups on the bare Au 2 B MBene and found that oxygen termination exhibited the most promising attachment. The phonon spectra, AIMD simulations, and cohesive energy calculation were used to identify the dynamic, thermal, and structural stability of Au 2 B and Au 2 BO 2 . Both the structures possess high conductive properties and energetically efficient interactions with Li and Na metal ions. The metallic characteristics of the Au 2 B and Au 2 BO 2 are retained post-adsorption of Li and Na metal ions, which provide a significant advantage for alkali metal ion batteries. Both Au 2 B and Au 2 BO 2 structures demonstrated excellent potential as anode materials for Li- and Na-ion batteries, offering low energy barriers for ionic transport and high storage capacities. With low open circuit voltage values, these materials emerged as promising candidates for next-generation energy storage applications. • O-functionalization of Au 2 B MBene monolayer improves its energy storage performance. • The adsorption energies of Au 2 B and Au 2 BO 2 MBenes are highly endothermic, supports multiple ion intercalation. • These MBenes exhibit high theoretical capacities for LIB and SIB on the bases of the multi-layer adsorption. • The diffusion energy barrier heights of Li and Na ions are notably low.