Effects of oxygen vacancy on the electrochemical properties of γ-V2O5 as cathode material for lithium-ion batteries: a first-principle study

• Published in: Journal of solid state electrochemistry 2021-07, Vol.25 (7), p.1999-2007
• Main Authors: Wu, Jiandong, Jia, Tingqing, Chao, Fenggang, Yang, Shaolin, Lu, Hui, Ma, Jinfu, Sheng, Zhilin, liu, Limeng, Chen, Yuhong
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Cathodes; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Diffusion coefficient; Electrochemical analysis; Electrochemistry; Electrode materials; Energy Storage; First principles; Ion diffusion; Ion storage; Lithium; Lithium-ion batteries; Open circuit voltage; Original Paper; Oxygen; Physical Chemistry; Rechargeable batteries; Vacancies; Vanadium pentoxide
• ISSN: 1432-8488; 1433-0768
• DOI: 10.1007/s10008-021-04981-3

Generating oxygen vacancies is an effective way to improve the lithium-ion storage performance of V 2 O 5 . However, the mechanism has not been theoretically investigated. In this study, first-principle calculations were performed to study the effect of oxygen vacancy on electrochemical properties of γ -V 2 O 5 as cathode material for lithium-ion batteries. γ -V 2 O 5 with oxygen vacancy mole fraction of 1.67% shows an open circuit voltage about 0.1 V lower than that of the perfect γ -V 2 O 5 . Oxygen vacancies generates gap states, which is beneficial to the electronic conductivity of γ -V 2 O 5 and γ -LiV 2 O 5 . In addition, the activation energies for lithium-ion diffusion along [010] in both γ -V 2 O 5 and γ -LiV 2 O 5 are increased by oxygen vacancy, which might lead to the decrease of diffusion coefficient. Our results will provide guidance for further improving the lithium-ion storage performance of γ -V 2 O 5 .