Ultrahigh capacity 2D anode materials for lithium/sodium-ion batteries: an entirely planar B₇P₂ monolayer with suitable pore size and distribution

Abstract

We propose that porous 2D materials with entirely planar structure and proper pore sizes are highly promising ultrahigh capacity anode materials for LIBs and SIBs, following which the B7P2 monolayer is identified with an ultrahigh capacity of 3117 mA h g−1.

All Boron Atoms in a ScB12 Monolayer Contribute to the Hydrogen Evolution Reaction

“…The thermodynamic stability of the ScB 12 monolayer is assessed by calculating its cohesive energy defined as E cof = ( E Sc + 12 E B – E ScB 12 )/13, in which E Sc , E B , and E ScB 12 are the energies of a single Sc atom, a single B atom, and one unit cell of the ScB 12 monolayer, respectively. The calculated cohesive energy of the ScB 12 monolayer (5.94 eV per atom) is comparable to three boron monolayers experimentally (5.90 eV per atom of triangular-borophene, 5.95 eV per atom of β 12 -borophene, 5.96 eV per atom of χ 3 -borophene), and it is slightly higher than that of previously reported 2D metal borides, such as the FeB 2 monolayer (5.62 eV per atom) and the AlB 6 nanosheet (5.74 eV per atom), and the B 7 P 2 monolayer containing the B 7 -unit (5.49 eV per atom) at the same computational level, suggesting a strongly bonded network and outstanding thermodynamic stability.…”

“…Unlike the upward trend of a-ΔG H with the increase of hydrogen coverage, the d-ΔG H values present a fluctuation with the increase of hydrogen coverage, which is similar to the trend of the Li/Na differential adsorption energy with the increase in the number of adsorbed atoms on the B 7 P 2 monolayer. 61 The best d-ΔG H is also 0.01 eV at the hydrogen coverage of 3/12, which is equal to a-ΔG H at identical hydrogen coverage.…”

Borophene-Based Three-Dimensional Porous Structures as Anode Materials for Alkali Metal-Ion Batteries with Ultrahigh Capacity

“…11−13 Among them, β 12 -borophene is predicted to possess ultrahigh capacities of 3968/1984 mA h/g for Li/Na-ions. 14,15 However, the anodic performance of β 12 -borophene is constrained by structural instability, small pore sizes, and poor hopping dynamics. 14,16,17 To overcome these difficulties, foreign atoms such as H, 18 O, 16 S, 19 and P 20 can be introduced to tune the pore sizes and reduce the diffusion barriers.…”

BC6P Monolayer: Isostructural and Isoelectronic Analogues of Graphene with Desirable Properties for K-Ion Batteries

“…The C-rich binary materials C 3 N, BC 3 , and TiC 3 are known for their favorable performance. Fully planar 2D materials, akin to graphene, are favorable for ion transport. , In this context, isoelectronic design is a promising approach to obtain materials with the desired properties . For example, 2D hexagonal BN is a wide band gap insulator, whereas isoelectronic graphene is gapless .…”