The global energy shortage and the gradual depletion of lithium resources have become increasingly prominent. Improving the energy density of lithium-based secondary batteries and developing other high-performance alkali-metal secondary batteries have become the research focus. In this study, two-dimensional (2D) hexagonal metal borides
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The global energy shortage and the gradual depletion of lithium resources have become increasingly prominent. Improving the energy density of lithium-based secondary batteries and developing other high-performance alkali-metal secondary batteries have become the research focus. In this study, two-dimensional (2D) hexagonal metal borides (
h-MBenes) are investigated as ordered alkali metal adsorption substrates for alkali-metal-based battery anode materials using density functional theory (DFT). Twelve thermodynamically stable
h-MBenes are screened out from thirty-three structures, and their excellent stability and metallic electronic characteristics are confirmed. The ordered multilayered growth in alkali metal adsorption is found to depend on two factors: low lattice mismatching and dynamic matching of the work function. In particular, Mg/Al/V-based
h-MBenes exhibit excellent lithium lattice matching (<3.35% mismatch), enabling layer-by-layer hexagonal (001) Li growth for ≥5 layers. They have ultrahigh lithium capacities (2170–3818 mAh·g
−1), low migration barriers (0.01–0.05 eV), and low voltages (0.003–0.714 V). Mg/Y-based
h-MBenes enable three Na layers’ adsorption with a capacity of 1717/605 mAh·g
−1, and Al
2B
2 achieves a 472 mAh·g
−1 potassium storage capacity, respectively. Due to the orderly multilayered growth mechanism, Mg/Al/V-based
h-MBenes show great potential as high-safety and ultrahigh-capacity alkali-metal battery anode materials.
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