A density functional theory study on the assessment of α-CN and α-CP monolayers as anode material in Li-ion batteries

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.…”

“…The Zn diffusion barrier for monolayer Ti 3 C 2 is 0.19 eV, which is close to the value for bilayer Ti 0.75 V 0.75 Cr 0.75 Mo 0.75 C 2 . The lowest barrier of 0.18 eV for Ti 0.75 V 0.75 Cr 0.75 Mo 0.75 C 2 , which is comparable with those of 2D α-CP and porous phosphorene (0.11–0.22 eV) , and superior to C 2 N (0.24–1 eV), TiS 2 (0.333 eV), TiSe 2 (0.338 eV), and h-AlC (0.41–1.21 eV) in Table ,,, 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), ,, 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.…”

“…When the adsorbed number of Zn atoms is 24, the calculated OCV value of the Ti 0.75 V 0.75 Cr 0.75 Mo 0.75 C 2 bilayer with Zn 2+ saturation is 0.23 V. The average OCV values for bilayer Ti 0.75 V 0.75 Cr 0.75 Mo 0.75 C 2 and Ti 3 C 2 are 0.63 and 0.54 V, respectively. Table exhibits the comparison of average OCVs, theoretical capacities, and diffusion energy barriers of some 2D anode materials for metal-ion batteries. ,− ,− The average OCV of bilayer Ti 0.75 V 0.75 Cr 0.75 Mo 0.75 C 2 is comparable with the values of 2D Mo 2 CrC 2 ,V 3 C 2 , Cr 3 C 2 , VHfMoC 2 (0.18–0.8 V), and C 2 N (0.26–1.40 V) ,,− in Table and is larger than other recent studies of 2D TiS 2 (∼0.3 V), TiSe 2 (∼0.1 V), α-BNP 2 (0.58 V), Mg 2 MnO 4 (0.6 V), and PC 6 (0.23 V). ,− These results reveal the excellent performance of Ti 0.75 V 0.75 Cr 0.75 Mo 0.75 C 2 nanosheets as an anode material with suitable electric potential for 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 .…”

“…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 .…”