title: Iron-Doped Cauliflower-Like Rutile TiO2with Superior Sodium Storage Properties.
abstract: Developing advanced anodes for sodium ion batteries is still challenging. In this work, Fe-doped three-dimensional (3D) cauliflower-like rutile TiO2was successfully synthesized by a facile hydrolysis method followed by a low-temperature annealing process. The influence of Fe content on the structure, morphology, and electrochemical performance was systematically investigated. When utilized as a sodium ion battery anode, 6.99%-Fe-doped TiO2exhibited the best electrochemical performance. This sample delivered a very high reversible capacity (327.1 mAh g-1at 16.8 mA g-1) and superior rate performance (160.5 mAh g-1at 840 mA g-1), as well as long-term cycling stability (no capacity fading at 1680 mA g-1over 3000 cycles). Density functional theory (DFT) calculations combined with experimental results indicated that the significantly improved sodium storage ability of the Fe-doped sample should be mainly due to the increased oxygen vacancies, narrowed band gap, and lowered sodiation energy barrier, which enabled much higher electronic/ionic conductivities and more favorable sodium ion intercalation into rutile TiO2.
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha 410083, P.R China.
authors.forename: Hanna
authors.initials: H
authors.lastname: He
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha 410083, P.R China.
authors.forename: Dan
authors.initials: D
authors.lastname: Sun
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha 410083, P.R China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Chemical and Biomolecular Engineering, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Fang
authors.initials: F
authors.lastname: Fu
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha 410083, P.R China.
authors.forename: Yougen
authors.initials: Y
authors.lastname: Tang
authors.affiliation: School of Chemistry and Materials Science, Guizhou Normal University , Guiyang 550001, P.R China.
authors.forename: Jun
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Chemical and Biomolecular Engineering, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Minhua
authors.identifier: http://orcid.org/0000-0003-4496-0057
authors.initials: M
authors.lastname: Shao
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha 410083, P.R China.|Department of Chemical and Biomolecular Engineering, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Haiyan
authors.identifier: http://orcid.org/0000-0002-2242-6534
authors.initials: H
authors.lastname: Wang
keywords: Fe-doped TiO2; density functional theory calculations; oxygen vacancies; rate performance; sodium ion battery