TY - JOUR
T1 - Assessing lithium storage capacities and ion diffusion dynamics in N-doped double-transition metal Mo2Ti(CxN1-x)2 and Mo2Ti(CxN1-x)2O2 MXenes
T2 - A first-principles calculations
AU - Liu, Jingya
AU - Jiang, Qin
AU - Liu, Haoliang
AU - Zeng, Chao
AU - Wu, Kai
AU - Wang, Hongkang
AU - Xu, Xin
AU - Cheng, Yonghong
AU - Xiao, Bing
N1 - Publisher Copyright:
© 2024 Elsevier B.V.
PY - 2024/2/15
Y1 - 2024/2/15
N2 - We employ the first-principles calculations to investigate the atomic structure, thermodynamic stability, and electrochemical energy storage properties of N-doped carbonitride and nitride double-transition metal MXenes including Mo2TiC2-Mo2TiN2 and Mo2TiC2O2-Mo2TiC2O2 series. The thermodynamic feasibility for the ammonization or nitrogenation of Mo2TiC2 and Mo2TiC2O2 monolayers to obtain Mo2Ti(CxN1-x)2 and Mo2Ti(CxN1-x)2O2 MXenes are evaluated by calculating the reaction enthalpies as a function of N content. It is found that ammonization of both bare and O-terminated MXenes is exothermic with a N content below 50 at.%, and which is slightly endothermic above this dopant concentration. Meanwhile, reaction enthalpy of nitrogenation of Mo2TiC2 or Mo2TiC2O2 MXenes is highly endothermic. Theoretical capacities of bare and O-terminated Mo2Ti(CxN1-x)2 and Mo2Ti(CxN1-x)2O2 MXenes are predicted to be in the range from 160 mAh/g to 350 mAh/g for lithium ion battery (LIB). Due to the presence of a multi-layer adsorption mechanism and the surface conversion reactions, Mo2Ti(CxN1-x)2O2 MXenes exhibit significantly higher theoretical capacities for LIB than bare carbide, carbonitride and nitride MXenes. For all studied bare and O-terminated MXenes, their mean open circuit voltages are found to be less than 1.0 V. For the Li+ diffusion dynamics, the diffusion coefficients of Mo2Ti(CxN1-x)2-Mo2TiN2 and Mo2Ti(CxN1-x)2O2-Mo2TiN2O2 series are predicted to be 0.45 ∼ 0.75 × 10−8 m2/s and 0.1 ∼ 0.2 × 10−8 m2/s at 350 K, respectively. The diffusion energy barrier heights of Li+ on Mo2Ti(CxN1-x)2 and Mo2Ti(CxN1-x)2O2 MXenes are found to be less than 0.1 eV for energetically favorable migration pathways. Overall, we predict that O-terminated carbonitride MXenes could possess both high storage capacity and high charge/discharge rate capability for their use as electrode materials in LIB.
AB - We employ the first-principles calculations to investigate the atomic structure, thermodynamic stability, and electrochemical energy storage properties of N-doped carbonitride and nitride double-transition metal MXenes including Mo2TiC2-Mo2TiN2 and Mo2TiC2O2-Mo2TiC2O2 series. The thermodynamic feasibility for the ammonization or nitrogenation of Mo2TiC2 and Mo2TiC2O2 monolayers to obtain Mo2Ti(CxN1-x)2 and Mo2Ti(CxN1-x)2O2 MXenes are evaluated by calculating the reaction enthalpies as a function of N content. It is found that ammonization of both bare and O-terminated MXenes is exothermic with a N content below 50 at.%, and which is slightly endothermic above this dopant concentration. Meanwhile, reaction enthalpy of nitrogenation of Mo2TiC2 or Mo2TiC2O2 MXenes is highly endothermic. Theoretical capacities of bare and O-terminated Mo2Ti(CxN1-x)2 and Mo2Ti(CxN1-x)2O2 MXenes are predicted to be in the range from 160 mAh/g to 350 mAh/g for lithium ion battery (LIB). Due to the presence of a multi-layer adsorption mechanism and the surface conversion reactions, Mo2Ti(CxN1-x)2O2 MXenes exhibit significantly higher theoretical capacities for LIB than bare carbide, carbonitride and nitride MXenes. For all studied bare and O-terminated MXenes, their mean open circuit voltages are found to be less than 1.0 V. For the Li+ diffusion dynamics, the diffusion coefficients of Mo2Ti(CxN1-x)2-Mo2TiN2 and Mo2Ti(CxN1-x)2O2-Mo2TiN2O2 series are predicted to be 0.45 ∼ 0.75 × 10−8 m2/s and 0.1 ∼ 0.2 × 10−8 m2/s at 350 K, respectively. The diffusion energy barrier heights of Li+ on Mo2Ti(CxN1-x)2 and Mo2Ti(CxN1-x)2O2 MXenes are found to be less than 0.1 eV for energetically favorable migration pathways. Overall, we predict that O-terminated carbonitride MXenes could possess both high storage capacity and high charge/discharge rate capability for their use as electrode materials in LIB.
KW - First-principles calculations
KW - Li-ion battery
KW - MXenes
KW - N-doping
UR - https://www.scopus.com/pages/publications/85184013211
U2 - 10.1016/j.commatsci.2024.112841
DO - 10.1016/j.commatsci.2024.112841
M3 - 文章
AN - SCOPUS:85184013211
SN - 0927-0256
VL - 235
JO - Computational Materials Science
JF - Computational Materials Science
M1 - 112841
ER -
