Novel boron nitride MXenes as promising energy storage materials

MXenes are promising materials for rechargeable metal ion batteries and supercapacitors due to their high energy storage capacities, high electrical and ionic conductivities, and ease of synthesis. In this study, we predict the structure and properties of hitherto unexplored Ti-boron nitride MXenes (Ti₃BN and Ti₃BNT₂ where T = F, O, OH) using high-throughput density functional theory calculations. We identify multiple stable structures exhibiting high thermodynamic and mechanical stability with B and N atoms evenly dispersed in the lattice sites. The predicted properties of the BN MXenes show remarkable similarities to their carbide counterparts, including in their metallicity, elastic constants, and cation absorption properties. Significantly, these novel MXene compounds display high lithium storage capacities (>250 mA h g^-1), as well as suitability for non-lithium ion storage (Na, K, Ca, Mg), making them attractive candidates for both batteries and supercapacitors. This class of MXenes therefore merits further theoretical and experimental investigation.