Abstract
Given the inherentcharacteristics of transition metal fluorides and open tunnel-type frameworks, intercalation-conversion-type FeF3 ·0.33H2 O has attracted widespread attention as a promising lithium-ion battery cathode material with high operating voltage and high energy density. However, its low electronic conductivity and poor structural stability impede its practical application in high-rate capacity and long-lifetime batteries. Herein, rod-likeNb-substituted FeF3 ·0.33H2 O (Nb-FeF3 ·0.33H2 O@C) nanocrystals with a carbon coating derived from in situ carbonization in an ionic liquid are deliberately designed and prepared. Based on first-principles calculations and electrochemical analysis, it is shown that substitution of Nb into a proportion of Fe sites can dramatically reduce the total energy of the system and the bandgap, thus boosting the structural stability and electronic conductivity of FeF3 ·0.33H2 O. Simultaneously, the combination of a surface conductive carbon coating and assembly of the nanoparticles into a rod-like mesoporous architecture can produce an omni-directional ion/electron transmission network and a robust 3D composite structure. The Nb-FeF3 ·0.33H2 O@C composite with 3% Nb-doping displays high capacity (583.2mAhg-1 at 0.2C), good rate capacity (187.8mAhg-1 at a high rate of 5.0 C), and excellent long-term cycle stability (160.4mAhg-1 after 300 long cycles).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
