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

Abstract

Abstract2D 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−B2N2 structure by assembling the orthorhombic B2N2 monolayer into t‐C24 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−B2N2 possesses excellent mechanical, thermal and dynamical stability. Different from the pristine h‐B2N2, an improved electrical conductivity is observed for 3D−B2N2 with a small band gap of 0.66 eV. Moreover, the low mass density, unique porous structure and strong adsorption energy make the 3D−B2N2 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−B2N2 anode deserves further experimental investigation for SIBs/PIBs.

Half‐Metallic PN2 Monolayer as High‐performance Anode Material for Metal Ion (Li, Na and K) Batteries: A First‐Principles Study

“…Three high symmetry adsorption sites were considered on the PN 2 monolayer (Figure 3a), including the top sites above P and N atoms (T P , T N ) and the hollow site above the center of PÀ N hexagon ring (H). To quantitatively estimate the adsorption strength of metal ions on the substrate, adsorption energy (E a ) is calculated by: [51,52]…”

“…[58] This highlights the PN 2 monolayer as a potential high-capacity anode material for LIBs, NIBs and KIBs. Meanwhile, we calculated the OCV at different metal atom intercalation stage as follows: [51,52] OCV¼ À E PN 2 þx 2 metal atom À E PN 2 þx 1 metal atom À ðx 2 À x 1 ÞE metal atom ðx 2 À x 1 Þe (4)…”