Structure, charge transfer, and kinetic properties of NaVPO4F with Na+ extraction: a comprehensive first-principles study. Issue 27 (19th June 2019)

• Record Type: Journal Article
• Authors: Mamoor, Muhammd; Lian, Ruqian; Wang, Dashuai; Meng, Xing; Chen, Gang; Wei, Yingjin
• Is Part Of: Physical chemistry chemical physics. Volume 21:Issue 27(2019)
• Page Start: 14612
• Page End: 14619
• Publication Date: 2019-06-19
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c9cp01819k
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : DFT calculations showed an intermediate phase appeared during desodiation of NaVPO4 F. When Na + concentration reached at x = 0.5, Na x VPO4 F underwent a phase transition from C 2/ c to P 2/ c and then P 2/ c changed to C 2/ c when material completely desodiated. Abstract : First-principles calculations combined with density functional theory were performed to illuminate the electrochemical properties of NaVPO4 F. During desodiation to VPO4 F, a ∼11% volume change was observed, which was ∼2% greater than that from LiVPO4 F to VPO4 F. An intermediate phase was observed while examining the structural stability during Na + extraction from NaVPO4 F. The voltage profile showed a distinct charging plateau positioned at ∼4.0 V. Bader charge analysis elucidated the reduction of charge-oriented V cations during Na + extraction. The achieved electron density profiles were examined to analyze the influence of Na + extraction on V–F and V–O bonds during the desodiation process. The most facile diffusion pathway for Na + was discerned, with a minimum energy barrier of 0.85 eV. On the basis of these results, NaVPO4 F was suggested as a promising cathode material for Na-ion batteries.