Rational design of h‐AlC monolayer as anode material for Mg‐ion battery: A DFT study

Abstract

In the present work, we have analyzed the suitability of two‐dimensional (2D) h‐AlC as a high‐capacity anode material for Mg‐ion batteries (MIBs) by employing first principles‐based density functional theory (DFT). The structural parameters, electronic band structure, partial density of states (PDOS), theoretical storage capacity (TSC), diffusion energy barrier (DEB), open‐circuit voltage (OCV), and room temperature stability (from ab initio molecular dynamic (AIMD) simulations) are calculated and discussed. The band structure of h‐AlC monolayer remains metallic for all considered adsorption concentrations of Mg‐atoms which indicates its good electrical conductivity. A significant quantity of charge is transferred from Mg atom to h‐AlC during adsorption of the Mg atom due to its lower electronegativity compared with the Al and C atoms. The calculated TSC is 1221.75 mAh g−1 which is higher than many anode materials. For MIBs, calculated DEB and OCV are 1.21 and 0.73 V, respectively. However, transition from planar structure to buckled structure takes place during the adsorption of more than 9 Mg‐atoms over h‐AlC. The lattice change is negligible during adsorption of Mg atoms. The AIMD calculations revels that the 9 and 18 Mg atoms adsorbed h‐AlC is stable at T = 300 K. The aforementioned findings suggest that h‐AlC can be anode material for MIBs.

First principles study of B7N5 as a high capacity electrode material for K-ion batteries

“…49 Another crucial parameter to evaluate the performance of anode materials is the value of OCV. 50 The corresponding OCV values for B 7 N 5 Li 2 , B 7 N 5 Na 2 and B 7 N 5 K 8 are 0.66 V, 0.22 V and 0.14 V, respectively, which are all located at the required range (0–1 V). These low average values of OCV will prevent the formation of dendrites and further improve the safety of battery performance.…”

First-Principles Studies on High-Entropy Ti0.75V0.75Cr0.75Mo0.75C2 MXene Nanosheets as Anode Materials in Zinc-Ion Batteries

“…Additionally, as the Ti 0.75 V 0.75 Cr 0.75 Mo 0.75 C 2 bilayer can contain more Zn atoms in the interlayer, the capacity of the Ti 0.75 V 0.75 Cr 0.75 Mo 0.75 C 2 bilayer with 24 Zn atoms can increase to 769.2 mAh/g (Figure b). The storage capacity of the Ti 0.75 V 0.75 Cr 0.75 Mo 0.75 C 2 nanosheet is smaller than those of 2D α-CP (1108.91 mAh/g) and h-AlC (1221.75 mAh/g), − but it is larger than the reported values of 2D C 2 N (411 mAh/g), V 3 C 2 (269.86–606.42 mAh/g), TiS 2 (239.3 mAh/g), TiSe 2 (130.2 mAh/g), and porous phosphorene (243.31 mAh/g) in Table , ,− and it is also better than those of 2D Cr 3 C 2 (298 mAh/g), VHfMoC 2 (153 mAh/g), TiVC (483 mAh/g), α 1 -BNP 2 (463.34 mAh/g), and ScO 2 (435 mAh/g) ,− , and comparable with Mo 2 CrC 2 (154.88–927.51 mAh/g) . These results suggest that bilayer Ti 0.75 V 0.75 Cr 0.75 Mo 0.75 C 2 with a large interlayer spacing possesses high capacity and is suitable for zinc-ion storage in batteries.…”

“…(0.333 eV), TiSe 2 (0.338 eV), and h-AlC (0.41−1.21 eV) in Table 3 21,22,73,74 and is also smaller than those of graphene (0.54 eV), δ-MnO 2 (0.63 eV), and Mg 2 MnO 4 (0.455 eV), 79,87,88 reveals that Ti 0.75 V 0.75 Cr 0.75 Mo 0.75 C 2 nanosheets can realize fast adsorption/desorption kinetics processes and high charge/discharge rates for anode applications in zinc-ion batteries.…”

“…Over the past few decades, two-dimensional (2D) materials have received wide attention due to their innovative electronic, photonic, magnetic, and electrochemical properties − since the discovery of graphene in 2004 . Transition metal oxides (TMOs), transition metal dichalcogenides (TMDs), phosphorene, , carbon- and nitrogen-based materials, − transition metal carbides and nitrides (MXenes), − and other 2D structures , have been explored due to their excellent electrochemical performance, which are significant for variable portable devices and electric vehicles. , TMOs and TMDs as anode materials possess advantages like high capacity and low cost, but their resistance is large, and the volume expansion is obviously large and irreversible capacity loss occurs during cycles. , The theoretical capacity of phosphorene is high, but the preparation is time-consuming with low yields, and the structural changes are large during reactions. , Although graphene is widely used as anode materials with high energy density, the power density is low and the capacity is limited . The band gap of h-BN is so large that it is not suitable as an electrode material .…”

“…Monolayer α-CN and α-CP have high theoretical capacity and the diffusion barrier of α-CN is low, indicating high ionic mobility . 2D h-AlN is semiconductive with not high capacity, while 2D h-AlC exhibits high theoretical capacity and the open circuit voltage (OCV) is moderate for anode applications. , Besides, 2D MXenes as widely used energy storage materials were first discovered in 2011 . Their general formula is M n +1 X n , in which M denotes an early transition metal, X represents carbon and/or nitrogen, and n is 1, 2, or 3 .…”