Three‐Dimensional Porous Diboron Dinitride as a High‐Performance Anode Material for Sodium/Potassium‐Ion Batteries: A First Principles Study

Abstract 2D boron nitride shows great promise in the photoelectric device, deep UV emitter and field effect transistor with good thermal stability, high mechanical robustness and chemical inertness; nonetheless, its inherently low electrical conductivity and small pore size have severely hindered the electrochemical kinetics and lead to a poor rate capability. Herein, we design a novel porous 3D−B 2 N 2 structure by assembling the orthorhombic B 2 N 2 monolayer into t‐C 24 lattice and assesse its feasibility as the anode material of sodium(SIBs)/potassium(PIBs) ion batteries. The ab initio molecular dynamics (AIMD) simulation, Born‐Huang criteria, phonon spectrum and cohesive energy calculations confirms that the resulting 3D−B 2 N 2 possesses excellent mechanical, thermal and dynamical stability. Different from the pristine h ‐B 2 N 2 , an improved electrical conductivity is observed for 3D−B 2 N 2 with a small band gap of 0.66 eV. Moreover, the low mass density, unique porous structure and strong adsorption energy make the 3D−B 2 N 2 an outstanding electrode material for SIBs/PIBs with high storage capacities of 599.90 (479.92) mA h/g, low averaged open circuit voltages of 0.13 (0.27) V, low diffusion barriers of 0.04 (0.008) eV, and small volume expansions of 0.96 % (2.63 %). All the encouraging findings reveal that the 3D−B 2 N 2 anode deserves further experimental investigation for SIBs/PIBs.