A new 3D metallic, ductile, and porous boron nitride as a promising anode material for sodium-ion batteries

Abstract

We propose a new stable three-dimensional (3D) porous and metallic boron nitride anode material, named h-B₁₀N₁₂, with good ductility for sodium-ion batteries (SIBs). Based on first-principles calculations and a tight-binding model, we demonstrate that the metallicity originates from the synergistic contribution of the p-orbital of the sp²-hybridized B and N atoms, while the ductility is due to the unique configurations of B–B and N–N dimers in the structure. More importantly, this boron nitride allotrope exhibits a high reversible capacity of 582.21 mA h g⁻¹ in gravimetric density and 663.72 mA h cm⁻³ in volumetric density, fast Na-ion transport dynamics with low energy barriers ranging from 0.06 to 0.12 eV, a small volume change of 2.77%, and a long cycle-life. This study not only expands the family of conventional boron nitride materials with new features, but also enriches the family of anode materials for SIBs with high performance.