Two-dimensional Dirac semimetal OD-BC₃ as an ultrahigh-performance anode for Li-, Na-, and K-ion batteries

The development of anode materials that integrate high electronic conductivity with efficient alkali-metal-ion storage capability is essential for advancing rechargeable batteries. In this study, a novel two-dimensional boron-carbon Dirac semimetal with a buckled monolayer structure, denoted as OD-BC₃ (octagonal-dodecagonal BC₃), is theoretically designed via first-principles calculations. The proposed structure inherits the high conductivity and open macroporous channels of its parent material (BODG), while the incorporation of electron-deficient boron active sites significantly enhances ion adsorption. OD-BC₃ demonstrates favorable kinetic, thermodynamic, and mechanical stability, alongside intrinsic semimetallic characteristics. As a multi-ion anode, it achieves high theoretical capacities of 1430, 1180, and 1144 mAh g^-1 for Li, Na, and K, respectively, coupled with low diffusion barriers (0.14-0.26 eV) and low open-circuit voltage (0.38-0.61 V). Moreover, it exhibits excellent interfacial compatibility with common electrolyte solvents. This work provides valuable theoretical insights for the rational design of high-performance anode materials for next-generation batteries.